ISO 1996-1:2016
(Main)Acoustics — Description, measurement and assessment of environmental noise — Part 1: Basic quantities and assessment procedures
Acoustics — Description, measurement and assessment of environmental noise — Part 1: Basic quantities and assessment procedures
ISO 1996-1:2016 defines the basic quantities to be used for the description of noise in community environments and describes basic assessment procedures. It also specifies methods to assess environmental noise and gives guidance on predicting the potential annoyance response of a community to long-term exposure from various types of environmental noises. The sound sources can be separate or in various combinations. Application of the method to predict annoyance response is limited to areas where people reside and to related long-term land uses. Community response to noise can vary differently among sound sources that are observed to have the same acoustic levels. This part of ISO 1996 describes adjustments for sounds that have different characteristics. The term "rating level" is used to describe physical sound predictions or measurements to which one or more adjustments have been added. On the basis of these rating levels, the long-term community response can be estimated. The sounds are assessed either singly or in combination, allowing for consideration, when deemed necessary by responsible authorities, of the special characteristics of their impulsiveness, tonality, and low-frequency content, and for the different characteristics of road-traffic noise, other forms of transportation noise (such as aircraft noise), and industrial noise. ISO 1996-1:2016 does not specify limits for environmental noise. NOTE 1 In acoustics, several different physical measures describing sound can have their level expressed in decibels (e.g. sound pressure, maximum sound pressure, and equivalent continuous sound pressure). The levels corresponding to these physical measures normally will differ for the same sound. This often leads to confusion. Therefore, it is necessary to specify the underlying physical quantity (e.g. sound pressure level, maximum sound pressure level, and equivalent continuous sound pressure level). NOTE 2 In this part of ISO 1996, quantities are expressed as levels in decibels. However, some countries validly express the underlying physical quantity, such as maximum sound pressure, in pascal or sound exposure in pascal-squared seconds. NOTE 3 ISO 1996‑2 deals with the determination of sound pressure levels.
Acoustique — Description, mesurage et évaluation du bruit de l'environnement — Partie 1: Grandeurs fondamentales et méthodes d'évaluation
Akustika - Opis, merjenje in ocena hrupa v okolju - 1. del: Osnovne veličine in ocenjevalni postopki
Ta del standarda ISO 1996 opredeljuje osnovne veličine, ki se uporabljajo za opis hrupa v bivalnem okolju, in opisuje osnovne postopke ocenjevanja. Določa tudi metode za ocenjevanje okoljskega hrupa in podaja navodila za napovedovanje možnega odziva skupnosti na motnjo s hrupom pri dolgoročni izpostavljenosti različnim vrstam okoljskega hrupa. Zvočni viri lahko delujejo ločeno ali v različnih kombinacijah. Uporaba metode za napovedovanje odziva na motnjo s hrupom je omejena na območja, kjer bivajo ljudje, in z njimi povezano dolgoročno uporabo prostora.
Odziv skupnosti na hrup zvočnih virov, ki dosegajo enake zvočne ravni,
je lahko različen. Ta del standarda ISO 1996 opisuje popravke zvokov, ki imajo različne
značilnosti. Izraz »ocenjena raven« se uporablja za opis fizikalnih napovedi zvoka ali za meritve, ki jim je bil dodan vsaj eden popravek. Na podlagi ocenjenih ravni je mogoče oceniti dolgoročni odziv skupnosti.
Zvoki so ocenjeni posamezno ali v kombinaciji, kar po potrebi omogoča,
da pristojni organi upoštevajo posebne značilnosti impulznosti, tonalitete in
zastopanosti nizkih frekvenc ter različne značilnosti hrupa cestnega prometa,
drugih oblik prevoza (na primer letalski hrup) in industrijskega hrupa.
Ta del standarda ISO 1996 ne določa mejnih vrednosti za okolijski hrup.
OPOMBA 1: V akustiki je več različnih fizikalnih kazalnikov, ki opisujejo zvok, izražen v decibelih (npr. raven zvočnega tlaka, najvišja raven zvočnega tlaka in enakovredna neprekinjena raven zvočnega tlaka). Ravni, ki ustrezajo tem fizikalnim kazalnikom, se za isto vrsto zvoka običajno razlikujejo. To pogosto vodi do zmede.
Zato je treba opredeliti osnovne fizikalne veličine (npr. raven zvočnega tlaka, najvišjo raven zvočnega tlaka in enakovredno neprekinjeno raven zvočnega tlaka).
OPOMBA 2: V tem delu standarda ISO 1996 so veličine izražene kot ravni v decibelih. Vendar v nekaterih državah je uveljavljeno izražanje z osnovnimi fizikalnimi veličinami, kot sta najvišja raven zvočnega tlaka v paskalih ali zvočna izpostavljenost v paskalkvadrat sekundah.
OPOMBA 3: Standard ISO 1996-2 obravnava določanje ravni zvočnega tlaka.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2016
$NXVWLND2SLVPHUMHQMHLQRFHQDKUXSDYRNROMXGHO 2VQRYQHYHOLþLQHLQ
RFHQMHYDOQLSRVWRSNL
Acoustics -- Description, measurement and assessment of environmental noise -- Part 1:
Basic quantities and assessment procedures
Acoustique -- Description, mesurage et évaluation du bruit de l'environnement -- Partie 1:
Grandeurs fondamentales et méthodes d'évaluation
Ta slovenski standard je istoveten z: ISO 1996-1:2016
ICS:
13.140 Vpliv hrupa na ljudi Noise with respect to human
beings
17.140.01 $NXVWLþQDPHUMHQMDLQ Acoustic measurements and
EODåHQMHKUXSDQDVSORãQR noise abatement in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
INTERNATIONAL ISO
STANDARD 1996-1
Third edition
2016-03-01
Acoustics — Description,
measurement and assessment of
environmental noise —
Part 1:
Basic quantities and assessment
procedures
Acoustique — Description, mesurage et évaluation du bruit de
l’environnement —
Partie 1: Grandeurs fondamentales et méthodes d’évaluation
Reference number
©
ISO 2016
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
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ii © ISO 2016 – All rights reserved
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Expression of levels . 2
3.2 Time intervals . 3
3.3 Ratings . 4
3.4 Sound designations . 4
3.5 Impulsive sound sources . 6
3.6 Day, evening, night sound levels . 6
4 Symbols . 7
5 Descriptors for environmental noise(s) . 8
5.1 Single events . 8
5.1.1 Descriptors . . . 8
5.1.2 Event duration . 8
5.2 Repetitive single events . 8
5.3 Continuous sound . 9
6 Noise annoyance . 9
6.1 Descriptors for community noise . 9
6.2 Frequency weightings . 9
6.3 Adjusted levels . 9
6.3.1 Adjusted sound exposure levels . 9
6.3.2 Adjusted equivalent continuous sound pressure level .10
6.4 Rating levels .10
6.4.1 One sound source .10
6.4.2 Combined sources .10
6.5 Composite whole-day rating levels .11
7 Noise limit requirements .11
7.1 General .11
7.2 Specifications.12
7.2.1 Noise descriptors.12
7.2.2 Relevant time intervals .12
7.2.3 Sound sources and their operating conditions .12
7.2.4 Locations . .12
7.2.5 Propagation conditions .13
7.2.6 Uncertainties .13
8 Reporting assessments of environmental noise(s) and estimation of long-term
community annoyance response .13
8.1 Estimation of long-term annoyance response of communities .13
8.2 Test report .13
Annex A (informative) Adjustments for sound source rating levels .15
Annex B (informative) High-energy impulse sounds .20
Annex C (informative) Sounds with strong low-frequency content .22
Annex D (informative) Relationships to estimate the percentage of a population highly
annoyed and the 95 % prediction interval as a function of adjusted day-evening-
night and day-night sound levels .24
Annex E (informative) Estimated prevalence of a population highly annoyed as a function
of adjusted day-evening-night or day-night sound levels using the community
tolerance level formulation .26
Annex F (informative) Estimated prevalence of a population highly annoyed as a function of
adjusted day-evening-night or day-night sound level using a regression formulation .33
Annex G (informative) Annoyance caused by exposure to sound in multi-source environments .39
Annex H (informative) Theory-based approach to predict the growth of annoyance.41
Bibliography .45
iv © ISO 2016 – All rights reserved
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 43, Acoustics, Subcommittee SC 1, Noise.
This third edition cancels and replaces the second edition (ISO 1996-1:2003), which has been technically
revised. In particular, the following subclauses and annexes have been added or revised: 3.6, 6.3.1, 6.5,
8.1, 8.2.1 i), Annex A, Annex D, Annex E, Annex F, Annex G, and Annex H.
ISO 1996 consists of the following parts, under the general title Acoustics — Description, measurement
and assessment of environmental noise:
— Part 1: Basic quantities and assessment procedures
— Part 2: Determination of sound pressure levels
Introduction
To be of practical use, any method of description, measurement, and assessment of environmental noise
is intended to be related in some way to what is known about human response to noise. Many adverse
consequences of environmental noise increase with increasing noise, but the precise dose-response
relationships involved continue to be the subject of scientific debate. In addition, it is important that
all methods used be practicable within the social, economic, and political climate in which they are
used. For these reasons, there is a very large range of different methods in use around the world for
different types of noise, and this creates considerable difficulties for international comparison and
understanding.
The broad aim of the ISO 1996 series is to contribute to the international harmonization of methods of
description, measurement, and assessment of environmental noise from all sources.
The methods and procedures described in this part of ISO 1996 are intended to be applicable to noise
from various sources, individually or in combination, which contribute to the total exposure at a site.
At the stage of technology at the time of publication of this part of ISO 1996, the evaluation of long-
term noise annoyance seems to be best met by adopting the adjusted A-weighted equivalent continuous
sound pressure level, which is termed a “rating level”.
The aim of the ISO 1996 series is to provide authorities with material for the description and assessment
of noise in community environments. Based on the principles described in this part of ISO 1996, national
standards, regulations, and corresponding acceptable limits for noise can be developed.
vi © ISO 2016 – All rights reserved
INTERNATIONAL STANDARD ISO 1996-1:2016(E)
Acoustics — Description, measurement and assessment of
environmental noise —
Part 1:
Basic quantities and assessment procedures
1 Scope
This part of ISO 1996 defines the basic quantities to be used for the description of noise in community
environments and describes basic assessment procedures. It also specifies methods to assess
environmental noise and gives guidance on predicting the potential annoyance response of a community
to long-term exposure from various types of environmental noises. The sound sources can be separate
or in various combinations. Application of the method to predict annoyance response is limited to areas
where people reside and to related long-term land uses.
Community response to noise can vary differently among sound sources that are observed to have
the same acoustic levels. This part of ISO 1996 describes adjustments for sounds that have different
characteristics. The term “rating level” is used to describe physical sound predictions or measurements
to which one or more adjustments have been added. On the basis of these rating levels, the long-term
community response can be estimated.
The sounds are assessed either singly or in combination, allowing for consideration, when deemed
necessary by responsible authorities, of the special characteristics of their impulsiveness, tonality,
and low-frequency content, and for the different characteristics of road-traffic noise, other forms of
transportation noise (such as aircraft noise), and industrial noise.
This part of ISO 1996 does not specify limits for environmental noise.
NOTE 1 In acoustics, several different physical measures describing sound can have their level expressed in
decibels (e.g. sound pressure, maximum sound pressure, and equivalent continuous sound pressure). The levels
corresponding to these physical measures normally will differ for the same sound. This often leads to confusion.
Therefore, it is necessary to specify the underlying physical quantity (e.g. sound pressure level, maximum sound
pressure level, and equivalent continuous sound pressure level).
NOTE 2 In this part of ISO 1996, quantities are expressed as levels in decibels. However, some countries
validly express the underlying physical quantity, such as maximum sound pressure, in pascal or sound exposure
in pascal-squared seconds.
NOTE 3 ISO 1996-2 deals with the determination of sound pressure levels.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
IEC 61672-1, Electroacoustics — Sound level meters — Part 1: Specifications
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 Expression of levels
NOTE For levels defined in 3.1.1 to 3.1.6, it is essential that frequency weighting or frequency bandwidth, as
applicable, be specified, and time weighting, if applicable, be specified.
3.1.1
time-weighted and frequency-weighted sound pressure level
ten times the logarithm to the base 10 of the ratio of the time-mean-square of the sound pressure to
the square of a reference value, being obtained with a standard frequency weighting and standard time
weighting
Note 1 to entry: Sound pressure is expressed in pascal (Pa).
Note 2 to entry: The reference value is 20 μPa.
Note 3 to entry: Time-weighted and frequency-weighted sound pressure level is expressed in decibels (dB).
Note 4 to entry: The standard frequency weightings are A-weighting and C-weighting as specified in IEC 61672-1,
and the standard time weightings are F-weighting and S-weighting as specified in IEC 61672-1.
3.1.2
maximum time-weighted and frequency-weighted sound pressure level
greatest time-weighted and frequency-weighted sound pressure level within a stated time interval
Note 1 to entry: Maximum time-weighted and frequency-weighted sound pressure level is expressed in
decibels (dB).
3.1.3
N percentage exceedance level
time-weighted and frequency-weighted sound pressure level that is exceeded for N % of the time
interval considered
Note 1 to entry: N percentage exceedance level is expressed in decibels (dB).
EXAMPLE L is the A-frequency-weighted, F-time-weighted sound pressure level exceeded for
AF95,1h
95 % of 1 h.
3.1.4
peak sound pressure level
ten times the logarithm to the base 10 of the ratio of the square of the peak sound pressure to the
square of the reference value
Note 1 to entry: The reference value is 20 μPa.
Note 2 to entry: Peak sound pressure level is expressed in decibels (dB).
Note 3 to entry: Peak sound pressure should be determined with a detector as defined in IEC 61672-1. IEC 61672-
1 only specifies the accuracy of a detector using C-weighting.
Note 4 to entry: The peak sound pressure is the maximum absolute value of the instantaneous sound pressure
during a stated time interval.
3.1.5
sound exposure level
L
E
ten times the logarithm to the base 10 of the ratio of the sound exposure, E, being the integral of the
square of the sound pressure, p, over a stated time interval or event of duration, T (starting at t and
ending at t ), to a reference value, E
2 0
E
L =10lg dB
E
E
where
2 © ISO 2016 – All rights reserved
t
Ep= ()ttd ;
∫
t
E = 400 µPa s
Note 1 to entry: Sound exposure is expressed in pascal-squared seconds. Sound exposure level is expressed in
decibels (dB).
Note 2 to entry: Because of practical limitations of the measuring instruments, p is always understood to denote
the square of a frequency-weighted and frequency band-limited sound pressure. If a specific frequency weighting
as specified in IEC 61672-1 is applied, this should be indicated by appropriate subscripts; e.g. E , denotes the
A 1 h
A-weighted sound exposure over 1 h.
Note 3 to entry: The duration, T, of the integration is included implicitly in the time integral and need not to
be reported explicitly. For measurements of sound exposure over a specified time interval, the duration of
integration should be reported and the notation should be L .
E,T
Note 4 to entry: For sound exposure levels of an event, the nature of the event should be stated.
Note 5 to entry: When applied to a single event, the sound exposure level is called “single-event sound
exposure level”.
3.1.6
equivalent continuous sound pressure level
L
eq,T
ten times the logarithm to the base 10 of the ratio of the time-average of the square of the sound
pressure, p, during a stated time interval of duration, T (starting at t and ending t ), to the square of
1 2
the reference sound pressure, p
Note 1 to entry: The A-weighted equivalent continuous sound pressure level is
t
1 2
pt()dt
A
∫
T t
L =10lg dB
Aeq,T
p
where
p (t) is the A-weighted instantaneous sound pressure at running time t;
A
p is equal to 20 µPa.
Note 2 to entry: The equivalent continuous sound pressure level is also termed “time-averaged sound pressure
level”. It is expressed in decibels (dB).
3.2 Time intervals
3.2.1
reference time interval
time interval to which the rating of the sound is referred
Note 1 to entry: The reference time interval may be specified in national or international standards or by
local authorities to cover typical human activities and variations in the operation of sound sources. Reference
time intervals can be, for example, part of a day, the full day, or a full week. Some countries define even longer
reference time intervals.
Note 2 to entry: Different levels or sets of levels may be specified for different reference time intervals.
3.2.2
long-term time interval
specified time interval over which the sound of a series of reference time intervals is averaged or
assessed
Note 1 to entry: The long-term time interval is determined for the purpose of describing environmental noise as
it is generally designated by responsible authorities.
Note 2 to entry: For long-term assessments and land-use planning, long-term time intervals that represent some
significant fraction of a year should be used (e.g. 3 months, 6 months, and 1 year).
3.3 Ratings
3.3.1
adjustment
quantity, positive or negative, constant or variable, that is added to a predicted or measured acoustical
level to account for some sound character, the time of day, or the source type
3.3.2
rating level
predicted or measured acoustic level to which an adjustment has been added
Note 1 to entry: Measurements such as day/night sound pressure level or day/evening/night sound pressure
level are examples of rating levels because they are calculated from sound measured or predicted over different
reference time periods, and adjustments are added to the reference time interval equivalent continuous sound
pressure levels based on the time of day.
Note 2 to entry: A rating level may be created by adding adjustments to a measured or predicted level(s) to
account for some character of the sound such as tonality or impulsiveness.
Note 3 to entry: A rating level may be created by adding adjustments to a measured or predicted level(s) to account
for differences between source types. For example, using road traffic as the base sound source, adjustments may
be applied to the levels for aircraft or railway sources.
3.4 Sound designations
NOTE See Figure 1.
3.4.1
total sound
totally encompassing sound in a given situation at a given time, usually composed of sound from many
sources near and far
a) Three specific sounds A, B, and C under consideration, the residual sound and the total sound
4 © ISO 2016 – All rights reserved
b) Two specific sounds A and B under consideration, the residual sound and the total sound
Key
1 total sound
2 specific sound A
3 specific sound B
4 specific sound C
5 residual sound
NOTE 1 The lowest residual sound level is obtained when all specific sounds are suppressed.
NOTE 2 The dotted area indicates the residual sound when sounds A, B, and C are suppressed.
NOTE 3 In Figure 1 b), the residual sound includes the specific sound C as it is not under consideration.
Figure 1 — Total, specific, and residual sound designations
3.4.2
specific sound
component of the total sound that can be specifically identified and which is associated with a
specific source
3.4.3
residual sound
total sound remaining at a given position in a given situation when the specific sounds under
consideration are suppressed
3.4.4
initial sound
total sound present in an initial situation before any change to the existing situation occurs
3.4.5
fluctuating sound
continuous sound whose sound pressure level varies significantly, but not in an impulsive manner,
during the observation period
3.4.6
intermittent sound
sound that is present at the observer only during certain time periods that occur at regular or irregular
time intervals and is such that the duration of each such occurrence is more than about 5 s
EXAMPLE Motor vehicle noise under conditions of small traffic volume, train noise, aircraft noise, and air-
compressor noise.
3.4.7
sound emergence
increase in the total sound in a given situation that results from the introduction of some specific sound
3.4.8
impulsive sound
sound characterized by brief bursts of sound pressure
Note 1 to entry: The duration of a single impulsive sound is usually less than 1 s.
3.4.9
tonal sound
sound characterized by a single-frequency component or narrow-band components that emerge audibly
from the total sound
3.5 Impulsive sound sources
NOTE At the time of publication of this part of ISO 1996, no mathematical descriptor exists which can define
unequivocally the presence of impulsive sound or can separate impulsive sounds into the categories given in
3.5.1 to 3.5.3. These three categories, however, have been found to correlate best with community response.
Thus, the sources of sound listed in 3.5.1 to 3.5.3 are used to define impulsive sound sources.
3.5.1
high-energy impulsive sound source
explosive source where the equivalent mass of TNT exceeds 50 g, or sources with comparable
characteristics and degree of intrusiveness
Note 1 to entry: Sources of sonic booms include such items as aircraft, rockets, artillery projectiles, armour
projectiles, and other similar sources. This category does not include the short duration sonic booms generated
by small arms fire and other similar sources.
EXAMPLE Quarry and mining explosions, sonic booms, demolition, or industrial processes that use high
explosives, explosive industrial circuit breakers, and military ordnance (e.g. armour, artillery, mortar fire,
bombs, explosive ignition of rockets, and missiles).
3.5.2
highly impulsive sound source
source with highly impulsive characteristics and a high degree of intrusiveness
EXAMPLE Small arms fire, hammering on metal or wood, nail guns, drop-hammer, pile driver, drop forging,
punch presses, pneumatic hammering, pavement breaking, or metal impacts in rail-yard shunting operations.
3.5.3
regular impulsive sound source
impulsive sound source that is neither highly impulsive nor high-energy impulsive sound source
Note 1 to entry: This category includes sounds that are sometimes described as impulsive, but are not normally
judged to be as intrusive as highly impulsive sounds.
EXAMPLE Slamming of car door, outdoor ball games, such as football (soccer) or basketball, and church
bells. Very fast pass-bys of low-flying military aircraft can also fall into this category.
3.6 Day, evening, night sound levels
3.6.1
day sound level
L
day,h
equivalent continuous sound pressure level when the reference time interval is the day
Note 1 to entry: Subscript h indicates the number of hours, e.g. L .
day,12
Note 2 to entry: A day is normally the 12 h between 7 h and 19 h or the 15 h between 7 h and 22 h. However,
individual countries define day differently, e.g. 6 h to 18 h or 6 h to 22 h.
6 © ISO 2016 – All rights reserved
3.6.2
evening sound level
L
evening,h
equivalent continuous sound pressure level when the reference time interval is the evening
Note 1 to entry: Subscript h indicates the number of hours, e.g. L .
evening,4
Note 2 to entry: An evening is normally the 4 h between 19 h and 23 h. However, individual countries define
evening differently, e.g. 18 h to 22 h.
3.6.3
night sound level
L
night,h
equivalent continuous sound pressure level when the reference time interval is the night
Note 1 to entry: Subscript h indicates the number of hours, e.g. L .
night,8
Note 2 to entry: A night is normally the 8 h between 23 h and 7 h or the 9 h between 22 h and 7 h. However,
individual countries define night differently, e.g. 22 h to 6 h.
3.6.4
day-evening-night sound level
L
den
day-evening-night-weighted sound pressure level is defined by
1
01, LL01,( +5ddB) 01,(L +10dB)
day,12 evening,4 night,8
Lt=⋅10 lg 10 +⋅t 10 +⋅t 10 dB
dend ay evening night
()
24h
where t , t , and t are expressed in hours and t + t + t = 24 h.
day evening night day evening night
Note 1 to entry: The default values for t , t , and t are 12 h, 4 h, and 8 h, respectively, but individual
day evening night
countries, e.g. EU member states, reduce the evening period.
3.6.5
day-night sound level
L
dn
day-night-weighted sound pressure level is defined by
1 01, LL01,( +10dB)
day,15 night,9
Lt=⋅10 lg 10 +⋅t 10 dB
dn ( day night ))
24h
where t and t are expressed in hours and t + t = 24 h.
day night day night
Note 1 to entry: The default values for t and t are 15 h and 9 h, respectively.
day night
3.6.6
community tolerance level
L
ct
day-night sound level at which 50 % of the people in a particular community are predicted to be highly
annoyed by noise exposure
Note 1 to entry: L is used as a parameter that accounts for differences between sources and/or communities
ct
when predicting the percentage highly annoyed by noise exposure.
Note 2 to entry: Annex H provides further information on L .
ct
4 Symbols
Symbols are given in Table 1 where the A-frequency weighting and F-time weighting are indicated
for illustrative purposes only (except for L where C-weighting normally is used but some other
Cpeak
weighting, except A-weighting, could be used). Other frequency and time weightings as defined in
IEC 61672-1 shall be substituted as appropriate and/or as required by responsible authorities.
Table 1 — Symbols for sound pressure and sound exposure levels
Quantity Symbol
Time-weighted and frequency-weighted sound pressure level L
pAF
Maximum time-weighted and frequency-weighted sound pressure level L
AFmax
Percentage exceedance level L
AFNT
Peak sound pressure level L
Cpeak
Sound exposure level L
EA
Equivalent-continuous sound pressure level L
Aeq,T
Rating sound exposure level L
RE
Rating equivalent continuous level L
Req,T
5 Descriptors for environmental noise(s)
5.1 Single events
5.1.1 Descriptors
Sounds from single events (such as the pass-by of a truck, the fly-by of an aircraft, or an explosion at
a quarry) are all examples of single-event sounds. A single-event sound can be characterized by many
descriptors. These descriptors include physical quantities and the corresponding levels in decibels.
Three descriptors are often used to describe the sound of single events. Frequency weighting A is used
except for high-energy impulsive sounds or sounds with strong low-frequency content. The preferred
three descriptors are the following:
a) the sound exposure level with specified frequency weighting;
b) the maximum sound pressure level with specified time weighting and frequency weighting;
c) the peak sound pressure level with specified frequency weighting.
It is not recommended to use A-weighted peak sound levels (see Clause 4).
5.1.2 Event duration
Event duration shall be specified relative to some characteristic of the sound, such as the number of
times that some fixed level was exceeded.
EXAMPLE The duration of a sound event can be defined as the total time that the sound pressure level is
within 10 dB of its maximum sound pressure level.
NOTE While the sound exposure level combines sound level and duration, the concept of event duration can
be useful to differentiate events. For example, an aircraft pass-by can have a duration of 10 s to 20 s, while the
duration of a gunshot is less than 1 s.
5.2 Repetitive single events
Repetitive single-event environmental sounds are typically re-occurrences of single-event sounds. For
example, aircraft noise, railway noise, or road-traffic noise with a low traffic volume, can be considered
as the sum of the sound from multiple individual events. Also, the sound from gunfire is the sum of the
sound from multiple individual gunshot sounds. In this part of ISO 1996, the description of all repetitive
single-event sound sources utilizes the sound exposure levels of the single-event sounds and the
corresponding number of events to determine the rating equivalent continuous sound pressure levels.
8 © ISO 2016 – All rights reserved
5.3 Continuous sound
Transformers, fans, and cooling towers are examples of continuous sound sources. The sound pressure
level of the sound from a continuous sound source can be constant, fluctuating, or slowly varying over a
time interval. Continuous sound is preferably described by the A-weighted equivalent continuous sound
pressure level over a specified time interval. For fluctuating and intermittent sounds, the A-weighted
maximum sound pressure level with a specified time weighting can also be used.
NOTE Depending on the situation, road-traffic noise can be classified as a continuous source or as the sum of
many repetitive single-event sounds.
6 Noise annoyance
6.1 Descriptors for community noise
This part of ISO 1996 provides guidance on the assessment of environmental noise from individual
sources or any combination of sources. Responsible authorities may decide what sources, if any, are to
be combined, and what adjustments, if any, are to be applied. If the sound has special characteristics,
then the rating equivalent continuous sound pressure level shall be the primary measure used to
describe the sound. Other measures such as the maximum sound pressure level, the (adjusted) sound
exposure level, or the peak sound pressure level also may be specified.
Research has shown that the frequency weighting A, alone, is not sufficient to assess sounds
characterized by tonality, impulsiveness, or strong low-frequency content. To estimate the long-
term annoyance response of a community to sounds with some of these special characteristics, an
adjustment, in decibels, is added to the A-weighted sound exposure level or A-weighted equivalent
continuous sound pressure level. Also, research has shown that different transportation sounds or
industrial sounds evoke different community annoyance responses for the same A-weighted equivalent
continuous sound pressure level. The Bibliography contains a list of reports and publications describing
the technical basis of the assessment and prediction methods of this part of ISO 1996.
6.2 Frequency weightings
Frequency weighting A is generally used to assess all sound sources except high-energy impulsive
sounds or sounds with strong low-frequency content. Frequency weighting A shall not be used to
measure peak sound pressure levels.
6.3 Adjusted levels
6.3.1 Adjusted sound exposure levels
When the sound exposure levels of single events can be measured separately or calculated, then the
following method shall be used. If, in a measurement situation, sounds from single events cannot be
distinguished from other sources, then the method of 6.3.2 shall be used.
For any single-event sound except high-energy impulsive sound or sounds having strong low-frequency
content, the adjusted sound exposure level L is given by the sound exposure level L for the ith
REij Eij
single-event sound plus the level adjustment K for the jth type of sound, expressed in decibels. Guidance
j
on adjustments for specific source categories and specific situations is given in Annexes A, B, E, and F.
In mathematical notation,
LL=+K (1)
REijEij j
NOTE This edition of this part of ISO 1996 introduces in 3.6.6 the concept of community tolerance level,
L ; see References [7] and [18] to better understand and rate the prevalence of annoyance in communities.
ct
The community tolerance level is explained in Annex H. Annex E provides a unified set of adjustments to the
day-evening-night sound level, L , and the day-night sound level, L , that follow directly, and hence, exactly
den dn
from the use of L . Annex F provides a unified set of adjustments to L and L that follow indirectly from the
ct den dn
differences between the prevalence of annoyance functions fit separately to the three categories of transportation
noise sources using the regression approach of Reference [15]. It is expected that countries will adopt either the
adjustments in Annex E or those in Annex F.
6.3.2 Adjusted equivalent continuous sound pressure level
Over a time interval, T , the adjusted equivalent continuous sound pressure level or rating level, L ,
n Req j,Tn
for the jth source, is given by the actual equivalent continuous sound pressure level, L , plus the
Aeq j,Tn
level adjustment K for the jth source, expressed in decibels. Guidance on adjustments for specific source
j
categories and specific situations are given in Annexes A, E, and F.
In mathematical notation,
LL=+K (2)
ReqAjT,,njeq Tn j
For adjustments that relate to the character of the sound, these adjustments shall only be applied
during the time that the specific character is present. For example, if sound is tonal in character, then
the adjustments shall only be applied when the tonal sound is perceivable.
6.4 Rating levels
6.4.1 One sound source
If for a time interval, T , only one sound source is of relevance, the rating level is the equivalent
n
continuous sound pressure level calculated using Formula (3) from the adjusted sound exposure levels
given by 6.3.1, or it is the adjusted equivalent continuous sound pressure level given by 6.3.2. Rating
levels can be developed for any of the time intervals defined in 3.2.
01, L
REij
L =10lg 10 dB (3)
∑
Req jT, n
T /t
n 0
i
where t = 1 s.
6.4.2 Combined sources
General guidance to assess rating levels for combined sources is given in Annex G. Combined-source
rating levels can be developed for any of the time intervals specified in 3.2. In general, the time interval
T is subdivided into time intervals T for each source j. The value of T is chosen in such a way that the
nj nj
adjustment in L is constant. The subdivision of T may be different for the different sources. The
Req j,Tnj
rating equivalent continuous sound pressure level is then given by
01, L
Req,jTnj
L =⋅10lg ∑T 10 dB (4)
∑
nj
Req,T
T
j
n
where
TT=
∑
nj
n
for each source j.
NOTE As a practical matter, Formula (4) is typically evaluated one source at a time.
10 © ISO 2016 – All rights reserved
6.5 Composite whole-day rating levels
Another widely used method to describe a community noise environment is to assess a whole-day
composite rating level from the rating levels during different periods of one whole day. For example, a
day-night rating level, L , is given by
Rdn
01,(LK+ ) 01,(LK+ )
d 24−d
d
Rd Rnn
L =⋅10lg 10 + ⋅10 dB (5)
Rdn
24 24
where
d is the number of daytime hours;
L is the rating level for daytime, including adjustments for sound sources and sound character;
Rd
L is the rating level for night-time, including adjustments for sound sources and sound
Rn
character;
K is the adjustment for daytime;
d
K is the adjustment for night-time.
n
A similar formula can be used to create a day-evening-night rating level, L :
Rden
01,(LK+ ),01()LK+ 0,,1()LK+
d e 24−−de
d e
Rd Re Rnn
L =⋅10lg 10 + ⋅10 + ⋅10 dB (6)
Rden
24 24 24
where
e is the number of evening hours;
L is the rating level for evening-time, including adjustments for sound sources and sound
Re
character;
K is the adjustment for evening-time;
e
and the other symbols are as defined for Formula (5).
Responsible authorities should set the choice of the duration of the day and those hours that comprise
the day.
If a jurisdiction includes weekend adjustments, then the rating level shall be calculated separately
for weekdays, Saturdays, and Sundays. The yearly average should include the correct proportion of
weekdays, Saturdays, and Sundays to portray the entire time period.
7 Noise limit requirements
7.1 General
Noise limits are set by responsible authorities on the basis of knowledge about the effects of noise
on human health and well-being (especially dose-response relationships on annoyance), taking into
account social and economic factors.
Such limits depend on many factors such as the time of day (e.g. day, evening, night, and 24 h), the
activities to be protected (e.g. outdoor or indoor living, communication in schools, and recreation
in parks), the type of sound source, and the situation (e.g. new residential developments in existing
situations, new industrial or transportation installations near exist
...
INTERNATIONAL ISO
STANDARD 1996-1
Third edition
2016-03-01
Acoustics — Description,
measurement and assessment of
environmental noise —
Part 1:
Basic quantities and assessment
procedures
Acoustique — Description, mesurage et évaluation du bruit de
l’environnement —
Partie 1: Grandeurs fondamentales et méthodes d’évaluation
Reference number
©
ISO 2016
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
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CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Expression of levels . 2
3.2 Time intervals . 3
3.3 Ratings . 4
3.4 Sound designations . 4
3.5 Impulsive sound sources . 6
3.6 Day, evening, night sound levels . 6
4 Symbols . 7
5 Descriptors for environmental noise(s) . 8
5.1 Single events . 8
5.1.1 Descriptors . . . 8
5.1.2 Event duration . 8
5.2 Repetitive single events . 8
5.3 Continuous sound . 9
6 Noise annoyance . 9
6.1 Descriptors for community noise . 9
6.2 Frequency weightings . 9
6.3 Adjusted levels . 9
6.3.1 Adjusted sound exposure levels . 9
6.3.2 Adjusted equivalent continuous sound pressure level .10
6.4 Rating levels .10
6.4.1 One sound source .10
6.4.2 Combined sources .10
6.5 Composite whole-day rating levels .11
7 Noise limit requirements .11
7.1 General .11
7.2 Specifications.12
7.2.1 Noise descriptors.12
7.2.2 Relevant time intervals .12
7.2.3 Sound sources and their operating conditions .12
7.2.4 Locations . .12
7.2.5 Propagation conditions .13
7.2.6 Uncertainties .13
8 Reporting assessments of environmental noise(s) and estimation of long-term
community annoyance response .13
8.1 Estimation of long-term annoyance response of communities .13
8.2 Test report .13
Annex A (informative) Adjustments for sound source rating levels .15
Annex B (informative) High-energy impulse sounds .20
Annex C (informative) Sounds with strong low-frequency content .22
Annex D (informative) Relationships to estimate the percentage of a population highly
annoyed and the 95 % prediction interval as a function of adjusted day-evening-
night and day-night sound levels .24
Annex E (informative) Estimated prevalence of a population highly annoyed as a function
of adjusted day-evening-night or day-night sound levels using the community
tolerance level formulation .26
Annex F (informative) Estimated prevalence of a population highly annoyed as a function of
adjusted day-evening-night or day-night sound level using a regression formulation .33
Annex G (informative) Annoyance caused by exposure to sound in multi-source environments .39
Annex H (informative) Theory-based approach to predict the growth of annoyance.41
Bibliography .45
iv © ISO 2016 – All rights reserved
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 43, Acoustics, Subcommittee SC 1, Noise.
This third edition cancels and replaces the second edition (ISO 1996-1:2003), which has been technically
revised. In particular, the following subclauses and annexes have been added or revised: 3.6, 6.3.1, 6.5,
8.1, 8.2.1 i), Annex A, Annex D, Annex E, Annex F, Annex G, and Annex H.
ISO 1996 consists of the following parts, under the general title Acoustics — Description, measurement
and assessment of environmental noise:
— Part 1: Basic quantities and assessment procedures
— Part 2: Determination of sound pressure levels
Introduction
To be of practical use, any method of description, measurement, and assessment of environmental noise
is intended to be related in some way to what is known about human response to noise. Many adverse
consequences of environmental noise increase with increasing noise, but the precise dose-response
relationships involved continue to be the subject of scientific debate. In addition, it is important that
all methods used be practicable within the social, economic, and political climate in which they are
used. For these reasons, there is a very large range of different methods in use around the world for
different types of noise, and this creates considerable difficulties for international comparison and
understanding.
The broad aim of the ISO 1996 series is to contribute to the international harmonization of methods of
description, measurement, and assessment of environmental noise from all sources.
The methods and procedures described in this part of ISO 1996 are intended to be applicable to noise
from various sources, individually or in combination, which contribute to the total exposure at a site.
At the stage of technology at the time of publication of this part of ISO 1996, the evaluation of long-
term noise annoyance seems to be best met by adopting the adjusted A-weighted equivalent continuous
sound pressure level, which is termed a “rating level”.
The aim of the ISO 1996 series is to provide authorities with material for the description and assessment
of noise in community environments. Based on the principles described in this part of ISO 1996, national
standards, regulations, and corresponding acceptable limits for noise can be developed.
vi © ISO 2016 – All rights reserved
INTERNATIONAL STANDARD ISO 1996-1:2016(E)
Acoustics — Description, measurement and assessment of
environmental noise —
Part 1:
Basic quantities and assessment procedures
1 Scope
This part of ISO 1996 defines the basic quantities to be used for the description of noise in community
environments and describes basic assessment procedures. It also specifies methods to assess
environmental noise and gives guidance on predicting the potential annoyance response of a community
to long-term exposure from various types of environmental noises. The sound sources can be separate
or in various combinations. Application of the method to predict annoyance response is limited to areas
where people reside and to related long-term land uses.
Community response to noise can vary differently among sound sources that are observed to have
the same acoustic levels. This part of ISO 1996 describes adjustments for sounds that have different
characteristics. The term “rating level” is used to describe physical sound predictions or measurements
to which one or more adjustments have been added. On the basis of these rating levels, the long-term
community response can be estimated.
The sounds are assessed either singly or in combination, allowing for consideration, when deemed
necessary by responsible authorities, of the special characteristics of their impulsiveness, tonality,
and low-frequency content, and for the different characteristics of road-traffic noise, other forms of
transportation noise (such as aircraft noise), and industrial noise.
This part of ISO 1996 does not specify limits for environmental noise.
NOTE 1 In acoustics, several different physical measures describing sound can have their level expressed in
decibels (e.g. sound pressure, maximum sound pressure, and equivalent continuous sound pressure). The levels
corresponding to these physical measures normally will differ for the same sound. This often leads to confusion.
Therefore, it is necessary to specify the underlying physical quantity (e.g. sound pressure level, maximum sound
pressure level, and equivalent continuous sound pressure level).
NOTE 2 In this part of ISO 1996, quantities are expressed as levels in decibels. However, some countries
validly express the underlying physical quantity, such as maximum sound pressure, in pascal or sound exposure
in pascal-squared seconds.
NOTE 3 ISO 1996-2 deals with the determination of sound pressure levels.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
IEC 61672-1, Electroacoustics — Sound level meters — Part 1: Specifications
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 Expression of levels
NOTE For levels defined in 3.1.1 to 3.1.6, it is essential that frequency weighting or frequency bandwidth, as
applicable, be specified, and time weighting, if applicable, be specified.
3.1.1
time-weighted and frequency-weighted sound pressure level
ten times the logarithm to the base 10 of the ratio of the time-mean-square of the sound pressure to
the square of a reference value, being obtained with a standard frequency weighting and standard time
weighting
Note 1 to entry: Sound pressure is expressed in pascal (Pa).
Note 2 to entry: The reference value is 20 μPa.
Note 3 to entry: Time-weighted and frequency-weighted sound pressure level is expressed in decibels (dB).
Note 4 to entry: The standard frequency weightings are A-weighting and C-weighting as specified in IEC 61672-1,
and the standard time weightings are F-weighting and S-weighting as specified in IEC 61672-1.
3.1.2
maximum time-weighted and frequency-weighted sound pressure level
greatest time-weighted and frequency-weighted sound pressure level within a stated time interval
Note 1 to entry: Maximum time-weighted and frequency-weighted sound pressure level is expressed in
decibels (dB).
3.1.3
N percentage exceedance level
time-weighted and frequency-weighted sound pressure level that is exceeded for N % of the time
interval considered
Note 1 to entry: N percentage exceedance level is expressed in decibels (dB).
EXAMPLE L is the A-frequency-weighted, F-time-weighted sound pressure level exceeded for
AF95,1h
95 % of 1 h.
3.1.4
peak sound pressure level
ten times the logarithm to the base 10 of the ratio of the square of the peak sound pressure to the
square of the reference value
Note 1 to entry: The reference value is 20 μPa.
Note 2 to entry: Peak sound pressure level is expressed in decibels (dB).
Note 3 to entry: Peak sound pressure should be determined with a detector as defined in IEC 61672-1. IEC 61672-
1 only specifies the accuracy of a detector using C-weighting.
Note 4 to entry: The peak sound pressure is the maximum absolute value of the instantaneous sound pressure
during a stated time interval.
3.1.5
sound exposure level
L
E
ten times the logarithm to the base 10 of the ratio of the sound exposure, E, being the integral of the
square of the sound pressure, p, over a stated time interval or event of duration, T (starting at t and
ending at t ), to a reference value, E
2 0
E
L =10lg dB
E
E
where
2 © ISO 2016 – All rights reserved
t
Ep= ()ttd ;
∫
t
E = 400 µPa s
Note 1 to entry: Sound exposure is expressed in pascal-squared seconds. Sound exposure level is expressed in
decibels (dB).
Note 2 to entry: Because of practical limitations of the measuring instruments, p is always understood to denote
the square of a frequency-weighted and frequency band-limited sound pressure. If a specific frequency weighting
as specified in IEC 61672-1 is applied, this should be indicated by appropriate subscripts; e.g. E , denotes the
A 1 h
A-weighted sound exposure over 1 h.
Note 3 to entry: The duration, T, of the integration is included implicitly in the time integral and need not to
be reported explicitly. For measurements of sound exposure over a specified time interval, the duration of
integration should be reported and the notation should be L .
E,T
Note 4 to entry: For sound exposure levels of an event, the nature of the event should be stated.
Note 5 to entry: When applied to a single event, the sound exposure level is called “single-event sound
exposure level”.
3.1.6
equivalent continuous sound pressure level
L
eq,T
ten times the logarithm to the base 10 of the ratio of the time-average of the square of the sound
pressure, p, during a stated time interval of duration, T (starting at t and ending t ), to the square of
1 2
the reference sound pressure, p
Note 1 to entry: The A-weighted equivalent continuous sound pressure level is
t
1 2
pt()dt
A
∫
T t
L =10lg dB
Aeq,T
p
where
p (t) is the A-weighted instantaneous sound pressure at running time t;
A
p is equal to 20 µPa.
Note 2 to entry: The equivalent continuous sound pressure level is also termed “time-averaged sound pressure
level”. It is expressed in decibels (dB).
3.2 Time intervals
3.2.1
reference time interval
time interval to which the rating of the sound is referred
Note 1 to entry: The reference time interval may be specified in national or international standards or by
local authorities to cover typical human activities and variations in the operation of sound sources. Reference
time intervals can be, for example, part of a day, the full day, or a full week. Some countries define even longer
reference time intervals.
Note 2 to entry: Different levels or sets of levels may be specified for different reference time intervals.
3.2.2
long-term time interval
specified time interval over which the sound of a series of reference time intervals is averaged or
assessed
Note 1 to entry: The long-term time interval is determined for the purpose of describing environmental noise as
it is generally designated by responsible authorities.
Note 2 to entry: For long-term assessments and land-use planning, long-term time intervals that represent some
significant fraction of a year should be used (e.g. 3 months, 6 months, and 1 year).
3.3 Ratings
3.3.1
adjustment
quantity, positive or negative, constant or variable, that is added to a predicted or measured acoustical
level to account for some sound character, the time of day, or the source type
3.3.2
rating level
predicted or measured acoustic level to which an adjustment has been added
Note 1 to entry: Measurements such as day/night sound pressure level or day/evening/night sound pressure
level are examples of rating levels because they are calculated from sound measured or predicted over different
reference time periods, and adjustments are added to the reference time interval equivalent continuous sound
pressure levels based on the time of day.
Note 2 to entry: A rating level may be created by adding adjustments to a measured or predicted level(s) to
account for some character of the sound such as tonality or impulsiveness.
Note 3 to entry: A rating level may be created by adding adjustments to a measured or predicted level(s) to account
for differences between source types. For example, using road traffic as the base sound source, adjustments may
be applied to the levels for aircraft or railway sources.
3.4 Sound designations
NOTE See Figure 1.
3.4.1
total sound
totally encompassing sound in a given situation at a given time, usually composed of sound from many
sources near and far
a) Three specific sounds A, B, and C under consideration, the residual sound and the total sound
4 © ISO 2016 – All rights reserved
b) Two specific sounds A and B under consideration, the residual sound and the total sound
Key
1 total sound
2 specific sound A
3 specific sound B
4 specific sound C
5 residual sound
NOTE 1 The lowest residual sound level is obtained when all specific sounds are suppressed.
NOTE 2 The dotted area indicates the residual sound when sounds A, B, and C are suppressed.
NOTE 3 In Figure 1 b), the residual sound includes the specific sound C as it is not under consideration.
Figure 1 — Total, specific, and residual sound designations
3.4.2
specific sound
component of the total sound that can be specifically identified and which is associated with a
specific source
3.4.3
residual sound
total sound remaining at a given position in a given situation when the specific sounds under
consideration are suppressed
3.4.4
initial sound
total sound present in an initial situation before any change to the existing situation occurs
3.4.5
fluctuating sound
continuous sound whose sound pressure level varies significantly, but not in an impulsive manner,
during the observation period
3.4.6
intermittent sound
sound that is present at the observer only during certain time periods that occur at regular or irregular
time intervals and is such that the duration of each such occurrence is more than about 5 s
EXAMPLE Motor vehicle noise under conditions of small traffic volume, train noise, aircraft noise, and air-
compressor noise.
3.4.7
sound emergence
increase in the total sound in a given situation that results from the introduction of some specific sound
3.4.8
impulsive sound
sound characterized by brief bursts of sound pressure
Note 1 to entry: The duration of a single impulsive sound is usually less than 1 s.
3.4.9
tonal sound
sound characterized by a single-frequency component or narrow-band components that emerge audibly
from the total sound
3.5 Impulsive sound sources
NOTE At the time of publication of this part of ISO 1996, no mathematical descriptor exists which can define
unequivocally the presence of impulsive sound or can separate impulsive sounds into the categories given in
3.5.1 to 3.5.3. These three categories, however, have been found to correlate best with community response.
Thus, the sources of sound listed in 3.5.1 to 3.5.3 are used to define impulsive sound sources.
3.5.1
high-energy impulsive sound source
explosive source where the equivalent mass of TNT exceeds 50 g, or sources with comparable
characteristics and degree of intrusiveness
Note 1 to entry: Sources of sonic booms include such items as aircraft, rockets, artillery projectiles, armour
projectiles, and other similar sources. This category does not include the short duration sonic booms generated
by small arms fire and other similar sources.
EXAMPLE Quarry and mining explosions, sonic booms, demolition, or industrial processes that use high
explosives, explosive industrial circuit breakers, and military ordnance (e.g. armour, artillery, mortar fire,
bombs, explosive ignition of rockets, and missiles).
3.5.2
highly impulsive sound source
source with highly impulsive characteristics and a high degree of intrusiveness
EXAMPLE Small arms fire, hammering on metal or wood, nail guns, drop-hammer, pile driver, drop forging,
punch presses, pneumatic hammering, pavement breaking, or metal impacts in rail-yard shunting operations.
3.5.3
regular impulsive sound source
impulsive sound source that is neither highly impulsive nor high-energy impulsive sound source
Note 1 to entry: This category includes sounds that are sometimes described as impulsive, but are not normally
judged to be as intrusive as highly impulsive sounds.
EXAMPLE Slamming of car door, outdoor ball games, such as football (soccer) or basketball, and church
bells. Very fast pass-bys of low-flying military aircraft can also fall into this category.
3.6 Day, evening, night sound levels
3.6.1
day sound level
L
day,h
equivalent continuous sound pressure level when the reference time interval is the day
Note 1 to entry: Subscript h indicates the number of hours, e.g. L .
day,12
Note 2 to entry: A day is normally the 12 h between 7 h and 19 h or the 15 h between 7 h and 22 h. However,
individual countries define day differently, e.g. 6 h to 18 h or 6 h to 22 h.
6 © ISO 2016 – All rights reserved
3.6.2
evening sound level
L
evening,h
equivalent continuous sound pressure level when the reference time interval is the evening
Note 1 to entry: Subscript h indicates the number of hours, e.g. L .
evening,4
Note 2 to entry: An evening is normally the 4 h between 19 h and 23 h. However, individual countries define
evening differently, e.g. 18 h to 22 h.
3.6.3
night sound level
L
night,h
equivalent continuous sound pressure level when the reference time interval is the night
Note 1 to entry: Subscript h indicates the number of hours, e.g. L .
night,8
Note 2 to entry: A night is normally the 8 h between 23 h and 7 h or the 9 h between 22 h and 7 h. However,
individual countries define night differently, e.g. 22 h to 6 h.
3.6.4
day-evening-night sound level
L
den
day-evening-night-weighted sound pressure level is defined by
1
01, LL01,( +5ddB) 01,(L +10dB)
day,12 evening,4 night,8
Lt=⋅10 lg 10 +⋅t 10 +⋅t 10 dB
dend ay evening night
()
24h
where t , t , and t are expressed in hours and t + t + t = 24 h.
day evening night day evening night
Note 1 to entry: The default values for t , t , and t are 12 h, 4 h, and 8 h, respectively, but individual
day evening night
countries, e.g. EU member states, reduce the evening period.
3.6.5
day-night sound level
L
dn
day-night-weighted sound pressure level is defined by
1 01, LL01,( +10dB)
day,15 night,9
Lt=⋅10 lg 10 +⋅t 10 dB
dn ( day night ))
24h
where t and t are expressed in hours and t + t = 24 h.
day night day night
Note 1 to entry: The default values for t and t are 15 h and 9 h, respectively.
day night
3.6.6
community tolerance level
L
ct
day-night sound level at which 50 % of the people in a particular community are predicted to be highly
annoyed by noise exposure
Note 1 to entry: L is used as a parameter that accounts for differences between sources and/or communities
ct
when predicting the percentage highly annoyed by noise exposure.
Note 2 to entry: Annex H provides further information on L .
ct
4 Symbols
Symbols are given in Table 1 where the A-frequency weighting and F-time weighting are indicated
for illustrative purposes only (except for L where C-weighting normally is used but some other
Cpeak
weighting, except A-weighting, could be used). Other frequency and time weightings as defined in
IEC 61672-1 shall be substituted as appropriate and/or as required by responsible authorities.
Table 1 — Symbols for sound pressure and sound exposure levels
Quantity Symbol
Time-weighted and frequency-weighted sound pressure level L
pAF
Maximum time-weighted and frequency-weighted sound pressure level L
AFmax
Percentage exceedance level L
AFNT
Peak sound pressure level L
Cpeak
Sound exposure level L
EA
Equivalent-continuous sound pressure level L
Aeq,T
Rating sound exposure level L
RE
Rating equivalent continuous level L
Req,T
5 Descriptors for environmental noise(s)
5.1 Single events
5.1.1 Descriptors
Sounds from single events (such as the pass-by of a truck, the fly-by of an aircraft, or an explosion at
a quarry) are all examples of single-event sounds. A single-event sound can be characterized by many
descriptors. These descriptors include physical quantities and the corresponding levels in decibels.
Three descriptors are often used to describe the sound of single events. Frequency weighting A is used
except for high-energy impulsive sounds or sounds with strong low-frequency content. The preferred
three descriptors are the following:
a) the sound exposure level with specified frequency weighting;
b) the maximum sound pressure level with specified time weighting and frequency weighting;
c) the peak sound pressure level with specified frequency weighting.
It is not recommended to use A-weighted peak sound levels (see Clause 4).
5.1.2 Event duration
Event duration shall be specified relative to some characteristic of the sound, such as the number of
times that some fixed level was exceeded.
EXAMPLE The duration of a sound event can be defined as the total time that the sound pressure level is
within 10 dB of its maximum sound pressure level.
NOTE While the sound exposure level combines sound level and duration, the concept of event duration can
be useful to differentiate events. For example, an aircraft pass-by can have a duration of 10 s to 20 s, while the
duration of a gunshot is less than 1 s.
5.2 Repetitive single events
Repetitive single-event environmental sounds are typically re-occurrences of single-event sounds. For
example, aircraft noise, railway noise, or road-traffic noise with a low traffic volume, can be considered
as the sum of the sound from multiple individual events. Also, the sound from gunfire is the sum of the
sound from multiple individual gunshot sounds. In this part of ISO 1996, the description of all repetitive
single-event sound sources utilizes the sound exposure levels of the single-event sounds and the
corresponding number of events to determine the rating equivalent continuous sound pressure levels.
8 © ISO 2016 – All rights reserved
5.3 Continuous sound
Transformers, fans, and cooling towers are examples of continuous sound sources. The sound pressure
level of the sound from a continuous sound source can be constant, fluctuating, or slowly varying over a
time interval. Continuous sound is preferably described by the A-weighted equivalent continuous sound
pressure level over a specified time interval. For fluctuating and intermittent sounds, the A-weighted
maximum sound pressure level with a specified time weighting can also be used.
NOTE Depending on the situation, road-traffic noise can be classified as a continuous source or as the sum of
many repetitive single-event sounds.
6 Noise annoyance
6.1 Descriptors for community noise
This part of ISO 1996 provides guidance on the assessment of environmental noise from individual
sources or any combination of sources. Responsible authorities may decide what sources, if any, are to
be combined, and what adjustments, if any, are to be applied. If the sound has special characteristics,
then the rating equivalent continuous sound pressure level shall be the primary measure used to
describe the sound. Other measures such as the maximum sound pressure level, the (adjusted) sound
exposure level, or the peak sound pressure level also may be specified.
Research has shown that the frequency weighting A, alone, is not sufficient to assess sounds
characterized by tonality, impulsiveness, or strong low-frequency content. To estimate the long-
term annoyance response of a community to sounds with some of these special characteristics, an
adjustment, in decibels, is added to the A-weighted sound exposure level or A-weighted equivalent
continuous sound pressure level. Also, research has shown that different transportation sounds or
industrial sounds evoke different community annoyance responses for the same A-weighted equivalent
continuous sound pressure level. The Bibliography contains a list of reports and publications describing
the technical basis of the assessment and prediction methods of this part of ISO 1996.
6.2 Frequency weightings
Frequency weighting A is generally used to assess all sound sources except high-energy impulsive
sounds or sounds with strong low-frequency content. Frequency weighting A shall not be used to
measure peak sound pressure levels.
6.3 Adjusted levels
6.3.1 Adjusted sound exposure levels
When the sound exposure levels of single events can be measured separately or calculated, then the
following method shall be used. If, in a measurement situation, sounds from single events cannot be
distinguished from other sources, then the method of 6.3.2 shall be used.
For any single-event sound except high-energy impulsive sound or sounds having strong low-frequency
content, the adjusted sound exposure level L is given by the sound exposure level L for the ith
REij Eij
single-event sound plus the level adjustment K for the jth type of sound, expressed in decibels. Guidance
j
on adjustments for specific source categories and specific situations is given in Annexes A, B, E, and F.
In mathematical notation,
LL=+K (1)
REijEij j
NOTE This edition of this part of ISO 1996 introduces in 3.6.6 the concept of community tolerance level,
L ; see References [7] and [18] to better understand and rate the prevalence of annoyance in communities.
ct
The community tolerance level is explained in Annex H. Annex E provides a unified set of adjustments to the
day-evening-night sound level, L , and the day-night sound level, L , that follow directly, and hence, exactly
den dn
from the use of L . Annex F provides a unified set of adjustments to L and L that follow indirectly from the
ct den dn
differences between the prevalence of annoyance functions fit separately to the three categories of transportation
noise sources using the regression approach of Reference [15]. It is expected that countries will adopt either the
adjustments in Annex E or those in Annex F.
6.3.2 Adjusted equivalent continuous sound pressure level
Over a time interval, T , the adjusted equivalent continuous sound pressure level or rating level, L ,
n Req j,Tn
for the jth source, is given by the actual equivalent continuous sound pressure level, L , plus the
Aeq j,Tn
level adjustment K for the jth source, expressed in decibels. Guidance on adjustments for specific source
j
categories and specific situations are given in Annexes A, E, and F.
In mathematical notation,
LL=+K (2)
ReqAjT,,njeq Tn j
For adjustments that relate to the character of the sound, these adjustments shall only be applied
during the time that the specific character is present. For example, if sound is tonal in character, then
the adjustments shall only be applied when the tonal sound is perceivable.
6.4 Rating levels
6.4.1 One sound source
If for a time interval, T , only one sound source is of relevance, the rating level is the equivalent
n
continuous sound pressure level calculated using Formula (3) from the adjusted sound exposure levels
given by 6.3.1, or it is the adjusted equivalent continuous sound pressure level given by 6.3.2. Rating
levels can be developed for any of the time intervals defined in 3.2.
01, L
REij
L =10lg 10 dB (3)
∑
Req jT, n
T /t
n 0
i
where t = 1 s.
6.4.2 Combined sources
General guidance to assess rating levels for combined sources is given in Annex G. Combined-source
rating levels can be developed for any of the time intervals specified in 3.2. In general, the time interval
T is subdivided into time intervals T for each source j. The value of T is chosen in such a way that the
nj nj
adjustment in L is constant. The subdivision of T may be different for the different sources. The
Req j,Tnj
rating equivalent continuous sound pressure level is then given by
01, L
Req,jTnj
L =⋅10lg ∑T 10 dB (4)
∑
nj
Req,T
T
j
n
where
TT=
∑
nj
n
for each source j.
NOTE As a practical matter, Formula (4) is typically evaluated one source at a time.
10 © ISO 2016 – All rights reserved
6.5 Composite whole-day rating levels
Another widely used method to describe a community noise environment is to assess a whole-day
composite rating level from the rating levels during different periods of one whole day. For example, a
day-night rating level, L , is given by
Rdn
01,(LK+ ) 01,(LK+ )
d 24−d
d
Rd Rnn
L =⋅10lg 10 + ⋅10 dB (5)
Rdn
24 24
where
d is the number of daytime hours;
L is the rating level for daytime, including adjustments for sound sources and sound character;
Rd
L is the rating level for night-time, including adjustments for sound sources and sound
Rn
character;
K is the adjustment for daytime;
d
K is the adjustment for night-time.
n
A similar formula can be used to create a day-evening-night rating level, L :
Rden
01,(LK+ ),01()LK+ 0,,1()LK+
d e 24−−de
d e
Rd Re Rnn
L =⋅10lg 10 + ⋅10 + ⋅10 dB (6)
Rden
24 24 24
where
e is the number of evening hours;
L is the rating level for evening-time, including adjustments for sound sources and sound
Re
character;
K is the adjustment for evening-time;
e
and the other symbols are as defined for Formula (5).
Responsible authorities should set the choice of the duration of the day and those hours that comprise
the day.
If a jurisdiction includes weekend adjustments, then the rating level shall be calculated separately
for weekdays, Saturdays, and Sundays. The yearly average should include the correct proportion of
weekdays, Saturdays, and Sundays to portray the entire time period.
7 Noise limit requirements
7.1 General
Noise limits are set by responsible authorities on the basis of knowledge about the effects of noise
on human health and well-being (especially dose-response relationships on annoyance), taking into
account social and economic factors.
Such limits depend on many factors such as the time of day (e.g. day, evening, night, and 24 h), the
activities to be protected (e.g. outdoor or indoor living, communication in schools, and recreation
in parks), the type of sound source, and the situation (e.g. new residential developments in existing
situations, new industrial or transportation installations near existing residential areas, and remedial
measures in existing situations).
Noise limit regulations comprise both limit values and procedures describing the circumstances under
which compliance with the regulations can be verified. These procedures can be based either on
calculations from sound prediction models or on measurements.
A procedure shall include the following elements:
a) one or more sound descriptors;
b) the relevant time intervals;
c) the source and its operating mode and environment;
d) the location(s) where the noise limits are to be verified;
e) the propagation conditions from source to receiver;
f) the method to take into account uncertainties to the prediction or measurement procedure;
g) the type and character of the area where the noise limits are to be used;
h) the criteria for assessing compliance with limits.
7.2 Specifications
7.2.1 Noise descriptors
The preferred noise descriptor for the specification of noise limits is the rating level during one or more
given reference time intervals. When using rating levels, the adjustments that have to be taken into
account shall be specified.
In some countries, differences in the assessment of sound sources are not taken into
...
S L O V E N S K I SIST ISO 1996-1
S T A N D A R D julij 2016
Akustika – Opis, merjenje in ocena hrupa v okolju –
1. del: Osnovne veličine in ocenjevalni postopki
Acoustics – Description, measurement and assessment of environmental noise –
Part 1: Basic quantities and assessment procedures
Acoustique – Description, mesurage et évaluation du bruit de I 'environnement –
Partie 1: Grandeurs fondamentales et méthodes d'évaluation
Referenčna oznaka
ICS 13.140; 17.140.01 SIST ISO 1996-1:2016 (sl)
Nadaljevanje na straneh 2 do 52
© 2025-06. Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega standarda ni dovoljeno.
SIST ISO 1996-1 : 2016
NACIONALNI UVOD
Standard SIST ISO 1996-1 (sl), Akustika – Opis, merjenje in ocena hrupa v okolju – 1. del: Osnovne
veličine in ocenjevalni postopki, 2016, ima status slovenskega standarda in je istoveten mednarodnemu
standardu ISO 1996-1 (en), Acoustics – Description, measurement and assessment of environmental
noise – Part 1: Basic quantities and assessment procedures, 2016.
Ta standard nadomešča SIST ISO 1996-1:2006.
NACIONALNI PREDGOVOR
Mednarodni standard ISO 1996-1:2016 je pripravil tehnični odbor Mednarodne organizacije za
standardizacijo ISO/TC 43 Akustika. Slovenski standard SIST ISO 1996-1:2016 je prevod
mednarodnega standarda ISO 1996-1:2016. V primeru spora glede besedila slovenskega prevoda v
tem standardu je odločilen izvirni mednarodni standard. Slovensko izdajo standarda je pripravil tehnični
odbor SIST/TC AKU Akustika.
V slovenski zakonodaji so nekateri kazalniki uporabljeni v poslovenjeni obliki in tako so upoštevani tudi
v besedilu tega slovenskega standarda, čeprav se v enačbah lahko pojavijo v angleški obliki. Tako velja:
t t , t = t , t = t , L L , L = L , L = T , L = L .
day = dan evening večer night noč day = dan evening večer night noč den dvn
Odločitev za izdajo tega standarda je 22. aprila 2016 sprejel SIST/TC AKU Akustika.
ZVEZA S STANDARDI
S privzemom tega mednarodnega standarda veljajo za omejeni namen referenčnih standardov vsi
standardi, navedeni v izvirniku, razen tistih, ki so že sprejeti v nacionalno standardizacijo:
SIST EN 61672-1 Elektroakustika – Merilniki ravni zvoka – 1. del: Specifikacije
OSNOVA ZA IZDAJO STANDARDA
– privzem standarda ISO 1996-1:2016
PREDHODNA IZDAJA
– SIST ISO 1996-1:2006, Akustika – Opis, merjenje in ocena hrupa v okolju – 1. del: Osnovne veličine
in ocenjevalni postopki
OPOMBE
– Povsod, kjer se v besedilu standarda uporablja izraz “mednarodni standard”, v SIST ISO 1996-
1:2016 to pomeni “slovenski standard”.
– Nacionalni uvod in nacionalni predgovor nista sestavni del standarda.
SIST ISO 1996-1 : 2016
VSEBINA Stran
Predgovor . 5
Uvod . 6
1 Področje uporabe . 7
2 Zveze s standardi . 7
3 Izrazi in definicije . 7
3.1 Izražanje ravni . 7
3.2 Časovni intervali . 9
3.3 Ocene . 9
3.4 Oznake zvoka .10
3.5 Viri impulznega zvoka.12
3.6 Dnevne, večerne, nočne ravni zvoka .13
4 Simboli .14
5 Kazalci (deskriptorji) hrupa v okolju .14
5.1 Posamični dogodki .14
5.1.1 Kazalci (deskriptorji) .14
5.1.2 Trajanje dogodka .15
5.2 Ponavljajoči se posamični dogodki .15
5.3 Neprekinjeni zvok .15
6 Vznemirjenost zaradi hrupa .15
6.1 Kazalci (deskriptorji) hrupa v življenjskem okolju .15
6.2 Frekvenčno vrednotenje .15
6.3 Popravljene ravni .16
6.3.1 Popravljene ekspozicijske ravni zvoka .16
6.3.2 Popravljena ekvivalentna neprekinjena raven zvočnega tlaka .16
6.4 Ocenjevanje ravni .16
6.4.1 En vir zvoka .16
6.4.2 Kombinirani viri .17
6.5 Sestavljene celodnevne ravni .17
7 Zahteve za omejitve hrupa .18
7.1 Splošno .18
7.2 Specifikacije .18
7.2.1 Kazalci (deskriptorji) hrupa .18
7.2.2 Relevantni časovni intervali .18
7.2.3 Viri zvoka in njihove obratovalne razmere.19
7.2.4 Lokacije .19
7.2.5 Pogoji za širjenje .19
7.2.6 Negotovosti .19
8 Poročanje o ocenjevanju hrupa v okolju in ocena dolgoročnega odziva skupnosti
na vznemirjenost zaradi hrupa .19
SIST ISO 1996-1 : 2016
8.1 Ocena dolgoročnega odziva skupnosti na vznemirjenost zaradi hrupa .19
8.2 Poročilo o preskusu .19
8.2.1 Postavke, ki se vključijo v poročilo, če so relevantne .19
8.2.2 Dodatne zahteve za poročanje o skladnosti z omejitvami .20
Dodatek A (informativni): Popravki za ocenjene ravni vira hrupa .21
Dodatek B (informativni): Visokoenergijski impulzni zvoki .26
Dodatek C (informativni): Zvoki z močno zastopanostjo nizkofrekvenčnih komponent .28
Dodatek D (informativni): Razmerja za oceno odstotka tistih, ki jih hrup zelo moti,
in 95-odstotni napovedni interval kot funkcija popravljenih dnevno-večerno-nočnih in
dnevno-nočnih ravni zvoka .29
Dodatek E (informativni): Ocenjena prevalenca velike vznemirjenosti zaradi hrupa med prebivalstvom
kot funkcija popravka dnevno-večerno-nočne ravni zvoka ali dnevno-nočne ravni zvoka
z enačbo tolerančne ravni skupnosti .31
Dodatek F (informativni): Ocenjena prevalenca vznemirjenosti zaradi hrupa kot funkcija popravka
dnevno-večerno-nočne ravni zvoka ali dnevno-nočne ravni zvoka z regresijsko enačbo .38
Dodatek G (informativni): Vznemirjenost zaradi izpostavljenosti zvoku v okolju z več viri .44
Dodatek H (informativni): Pristop, ki temelji na teoriji za napovedovanje vznemirjenosti .46
Literatura.50
SIST ISO 1996-1 : 2016
Predgovor
Mednarodna organizacija za standardizacijo (ISO) je svetovna zveza nacionalnih organov za standarde
(članov ISO). Mednarodne standarde po navadi pripravljajo tehnični odbori ISO. Vsak član, ki želi
delovati na določenem področju, za katerega je bil ustanovljen tehnični odbor, ima pravico biti zastopan
v tem odboru. Pri delu sodelujejo tudi vladne in nevladne mednarodne organizacije, povezane z ISO. V
vseh zadevah, ki so povezane s standardizacijo na področju elektrotehnike, ISO tesno sodeluje z
Mednarodno elektrotehniško komisijo (IEC).
Postopki, uporabljeni pri pripravi tega dokumenta, in predvideni postopki za njegovo vzdrževanje so
opisani v Direktivah ISO/IEC, 1. del. Posebno pozornost je priporočljivo nameniti različnim kriterijem
odobritve, potrebnim za različne vrste dokumentov ISO. Ta dokument je bil pripravljen v skladu z
uredniškimi pravili Direktiv ISO/IEC, 2. del (glej www.iso.org/directives).
Opozoriti je treba na možnost, da so lahko nekateri elementi tega mednarodnega standarda predmet
patentnih pravic. ISO ne prevzema odgovornosti za identifikacijo katerihkoli ali vseh takih patentnih
pravic. Podrobnosti o morebitnih patentnih pravicah, opredeljenih med pripravo tega dokumenta, bodo
navedene v uvodu in/ali na seznamu patentnih izjav, ki jih je prejela organizacija ISO (glej
www.iso.org/patents).
Morebitna trgovska imena, uporabljena v tem dokumentu, so informacije za uporabnike in ne pomenijo
podpore blagovni znamki.
Za razlago pomena specifičnih terminov in izrazov ISO, povezanih z ugotavljanjem skladnosti, ter
informacije o tem, kako ISO upošteva načela WTO o tehničnih ovirah pri trgovanju (TBT), glej naslednjo
povezavo: Predgovor - Dodatne informacije
Odbor, ki je odgovoren za ta dokument, je tehnični odbor ISO/TC 43 Akustika, pododbor SC 1 Hrup.
Ta tretja izdaja razveljavlja in nadomešča drugo izdajo (ISO 1996-2:2003), ki je strokovno revidirana.
Dodani ali revidirani so bili naslednje podtočke in dodatki: 3.6, 6.3.1, 6.5, 8.1, 8.2.1 i), dodatek A, dodatek
D, dodatek E, dodatek F, dodatek G in dodatek H.
ISO 1996 sestavljata naslednja dela pod skupnim naslovom Akustika – Opis, merjenje in ocena hrupa
v okolju:
‒ 1. del: Osnovne veličine in ocenjevalni postopki
‒ 2. del: Določanje ravni hrupa v okolju
SIST ISO 1996-1 : 2016
Uvod
Za praktično uporabnost tega standarda naj bi se vse metode opisa, merjenja in ocenjevanja hrupa v
okolju na določen način povezale z odzivom človeka na hrup. Povečanje hrupa prinaša številne škodljive
posledice za okolje, vendar pa natančna povezava med dozo in učinkom še vedno ostaja predmet
znanstvenih razprav. Poleg tega je pomembno, da so vse uporabljene metode praktično izvedljive v
družbenem, gospodarskem in političnem okolju, v katerem so uporabljene. Posledično je po svetu na
voljo širok nabor različnih metod, ki se uporabljajo za različne vrste hrupa, kar predstavlja veliko težavo
pri mednarodni primerjavi in razumevanju.
Splošni cilj skupine standardov ISO 1996 je prispevati k mednarodnemu usklajevanju metod za opis,
merjenje in ocenjevanje hrupa v okolju iz vseh vrst virov.
Metode in postopki, opisani v tem delu ISO 1996, so namenjeni uporabi pri hrupu, ki izvira iz različnih
virov, bodisi posameznih bodisi v kombinaciji, in prispevajo k skupni izpostavljenosti na mestu merjenja.
Glede na tehnološke razmere ob času objave tega dela ISO 1996 se zdi, da je za ovrednotenje
dolgotrajne vznemirjenosti, ki jo povzroča hrup, najprimernejša uporaba popravljene A-vrednotene
ekvivalentne neprekinjene ravni zvočnega tlaka, znane kot "ocenjena raven".
Cilj skupine standardov ISO 1996 je oblastem zagotoviti podlago za opis in ocenjevanje hrupa v
bivalnem okolju. Na podlagi načel, opisanih v tem delu ISO 1996, je mogoče pripraviti ustrezne
nacionalne standarde, pravilnike in določiti sprejemljive mejne vrednosti hrupa.
SIST ISO 1996-1 : 2016
Akustika – Opis, merjenje in ocena hrupa v okolju – 1. del: Osnovne veličine in
ocenjevalni postopki
1 Področje uporabe
Ta del ISO 1996 opredeljuje osnovne veličine, ki se uporabljajo za opis hrupa v bivalnem okolju, opisuje
pa tudi osnovne postopke ocenjevanja. Prav tako določa metode za ocenjevanje hrupa v okolju in daje
navodila za napovedovanje možnega odziva skupnosti na vznemirjenost zaradi hrupa pri dolgotrajni
izpostavljenosti različnim vrstam hrupa v okolju. Viri zvoka lahko delujejo ločeno ali v različnih
kombinacijah. Uporaba metode za napovedovanje odziva na vznemirjenost zaradi hrupa je omejena na
območja, kjer bivajo ljudje, in s povezanimi dolgoročnimi rabami zemljišč.
Odziv skupnosti na hrup iz različnih virov zvoka, ki dosegajo enake ravni zvoka, je lahko različen. Ta
del ISO 1996 opisuje popravke zaradi zvokov, ki imajo različne značilnosti. Izraz "ocenjena raven" se
uporablja za opis fizikalnih napovedi ali meritev zvoka, ki vsebujejo en ali več popravkov. Na podlagi
ocenjenih ravni je mogoče oceniti dolgoročni odziv skupnosti.
Zvoki so ocenjeni bodisi posamezno ali v kombinaciji, kar po potrebi nudi možnost, da pristojni organi
upoštevajo posebne značilnosti impulzivnosti, tonalnosti, zastopanost nizkih frekvenc in različne
značilnosti hrupa cestnega prometa, drugih oblik prevoza (na primer hrupa letal) in industrijskega hrupa.
Ta del ISO 1996 ne določa mejnih vrednosti za hrup v okolju.
OPOMBA 1: V akustiki je več različnih fizikalnih kazalnikov, ki opisujejo zvok, izražen v decibelih (npr. zvočni tlak, največji
zvočni tlak in ekvivalentni neprekinjeni zvočni tlak). Ravni, ki ustrezajo tem fizikalnim kazalnikom, se navadno
razlikujejo že za isti zvok. To pogosto vodi do zmede. Zato je treba opredeliti pripadajoče osnovne fizikalne
veličine (npr. zvočni tlak, največji zvočni tlak in ekvivalentni neprekinjeni zvočni tlak).
OPOMBA 2: V tem delu ISO 1996 so veličine izražene kot ravni v decibelih. V nekaterih državah pa je uveljavljeno izražanje z
osnovnimi fizikalnimi veličinami, kot sta maksimalna raven zvočnega tlaka v paskalih ali zvočna ekspozicija v
paskalkvadrat sekundah.
OPOMBA 3: ISO 1996-2 obravnava določitev ravni zvočnega tlaka.
2 Zveze s standardi
Navedeni dokumenti so v celoti ali v delih povezani s tem dokumentom in so nepogrešljivi pri njegovi
uporabi. Pri datiranih sklicevanjih velja le navedena izdaja. Pri nedatiranih sklicevanjih se uporablja
zadnja izdaja citiranega dokumenta (vključno z morebitnimi dopolnili).
EN 61672-1 Elektroakustika – Merilniki ravni zvoka – 1. del: Specifikacije
3 Izrazi in definicije
V tem dokumentu so uporabljeni naslednji izrazi in definicije.
3.1 Izražanje ravni
OPOMBA: Za ravni, opredeljene v točkah od 3.1.1 do 3.1.6, je nujno, da se navedeta frekvenčna širina ali frekvenčno
vrednotenje in časovno vrednotenje.
3.1.1
časovno in frekvenčno vrednotena raven zvočnega tlaka
desetkratnik desetiškega logaritma razmerja med kvadratom časovno povprečnega zvočnega tlaka in
kvadratom referenčne vrednosti, ki se dobi s standardnim frekvenčnim vrednotenjem in standardnim
časovnim vrednotenjem
Opomba 1: Zvočni tlak je izražen v paskalih (Pa).
Opomba 2: Referenčna vrednost je 20 μPa.
SIST ISO 1996-1 : 2016
Opomba 3: Časovno in frekvenčno vrednotena raven zvočnega tlaka je izražena v decibelih (dB).
Opomba 4: Standardni frekvenčni vrednotenji sta A-vrednotenje in C-vrednotenje, kot sta določeni v IEC 61672-1, standardni
časovni vrednotenji pa sta F-vrednotenje in S-vrednotenje, kot sta določeni v IEC 61672-1.
3.1.2
maksimalna raven časovno in frekvenčno vrednotene ravni zvočnega tlaka
maksimalna raven časovno in frekvenčno vrednotene ravni zvočnega tlaka znotraj obravnavanega
časovnega intervala
Opomba 1: Maksimalna raven časovno in frekvenčno vrednotenega zvočnega tlaka je izražena v decibelih (dB).
3.1.3
N-percentilna raven
časovno in frekvenčno vrednotena raven zvočnega tlaka, ki je presežena N % obravnavanega
časovnega intervala
Opomba 1: N-percentilna raven je izražena v decibelih (dB).
PRIMER: L je frekvenčno A-vrednotena, časovno F-vrednotena raven zvočnega tlaka, ki je presežena 95 % v času trajanja ene ure.
AF95,1h
3.1.4
vršna raven zvočnega tlaka
desetkratnik desetiškega logaritma razmerja med kvadratom vršne ravni zvočnega tlaka in kvadratom
referenčne vrednosti
Opomba 1: Referenčna vrednost je 20 μPa.
Opomba 2: Vršna raven zvočnega tlaka je izražena v decibelih (dB).
Opomba 3: Vršna raven zvočnega tlaka naj se določi z detektorjem, kot je opredeljeno v IEC 61672-1. IEC 61672-1 določa
le točnost detektorja z uporabo C-vrednotenja.
Opomba 4: Vršna raven zvočnega tlaka je maksimalna absolutna vrednost trenutnega zvočnega tlaka v določenem
časovnem intervalu.
3.1.5
ekspozicijska raven zvoka
L
E
desetkratnik desetiškega logaritma razmerja zvočne ekspozicije E, ki je integral kvadrata zvočnega tlaka
p v določenem časovnem intervalu ali trajanju dogodka T (ki se začne pri t in konča pri t ), in referenčne
1 2
vrednosti E
kjer sta:
Opomba 1: Zvočna ekspozicija je izražena v Pa s. Ekspozicijska raven zvoka je izražena v decibelih (dB).
Opomba 2: Zaradi praktičnih omejitev merilnih instrumentov je vedno razumljeno, da p označuje kvadrat frekvenčno
vrednotenega in frekvenčno pasovno omejenega zvočnega tlaka. Če se uporabi določeno frekvenčno
vrednotenje, kot je določeno v IEC 61672-1, naj bo to označeno z ustreznimi podpisanimi oznakami; npr.
E označuje A-vrednoteno ekspozicijsko raven zvoka v 1 uri.
A,1 h
Opomba 3: Trajanje integracije, T, je vključeno posredno v časovni integral in ga ni treba izrecno navajati. Za meritve zvočne
ekspozicije v določenem časovnem intervalu naj se navede trajanje integracije in se zapiše kot L .
E,T
SIST ISO 1996-1 : 2016
Opomba 4: Za ekspozicijske ravni zvoka pri določenem dogodku naj se navede vrsta dogodka.
Opomba 5: Kadar se ekspozicijska raven zvoka uporabi za en dogodek, se imenuje "ekspozicijska raven zvoka posameznega
dogodka".
3.1.6
ekvivalentna neprekinjena raven zvočnega tlaka
L
eq,T
desetkratnik desetiškega logaritma razmerja med časovno povprečenim kvadratom zvočnega tlaka, p,
v določenem časovnem intervalu, T (ki se začne pri t in konča pri t ), in kvadratom referenčnega
1 2
zvočnega tlaka, p
Opomba 1: A-vrednotena ekvivalentna neprekinjena raven zvočnega tlaka je:
kjer sta:
pA(t) trenutna A-vrednotena raven zvočnega tlaka v času t
p je enako 20 μPa.
Opomba 2: Ekvivalentna neprekinjena raven zvočnega tlaka se lahko poimenuje tudi "časovno povprečena raven zvočnega
tlaka". Izražena je v decibelih (dB).
3.2 Časovni intervali
3.2.1
referenčni časovni interval
časovni interval, na katerega se nanaša ocenjevanje zvoka
Opomba 1: Referenčni časovni interval se lahko določi v nacionalnih ali mednarodnih standardih ali ga določijo lokalne oblasti
tako, da zajame tipične človeške dejavnosti in spremembe v delovanju virov zvoka. Referenčni časovni interval
je lahko na primer del dneva, cel dan ali cel teden. V nekaterih državah imajo določene celo daljše referenčne
časovne intervale.
Opomba 2: Za različne referenčne časovne intervale so lahko določene različne ravni ali skupine ravni.
3.2.2
dolgotrajni časovni interval
določen časovni interval, v katerem se povpreči oziroma ocenjuje več različnih referenčnih intervalov
Opomba 1: Dolgotrajni časovni interval je določen z namenom, da se opiše hrup v okolju, in ga navadno načrtujejo pristojni
organi.
Opomba 2: Dolgotrajni časovni interval, ki predstavlja znatne deleže leta (npr. 3 mesece, 6 mesecev in 1 leto), je priporočljivo
uporabiti za dolgoročno ocenjevanje in načrtovanje rabe zemljišč.
3.3 Ocene
3.3.1
popravek
veličina, pozitivna ali negativna, stalna ali spremenljiva, ki se prišteje k napovedani ali izmerjeni akustični
ravni zaradi upoštevanja neke zvočne značilnosti, obdobja dneva ali vrste vira zvoka
SIST ISO 1996-1 : 2016
3.3.2
ocenjena raven
napovedana ali izmerjena akustična raven, kateri je bil prištet popravek
Opomba 1: Meritve, kot so dnevne/nočne ravni zvočnega tlaka ali dnevne/večerne/nočne ravni zvočnega tlaka so primeri
ocenjenih ravni, ker so izračunane iz izmerjenega ali napovedanega zvoka v različnih obdobjih referenčnega časa
in se ti popravki prištejejo k ekvivalentni neprekinjeni ravni zvočnega tlaka v referenčnem času glede na obdobje
dneva.
Opomba 2: Ocenjena raven se lahko dobi s prištevanjem popravkov k izmerjeni(-m) ali napovedani(-m) ravni(-em) zaradi
neke zvočne značilnosti, kot sta tonaliteta ali impulznost.
Opomba 3: Ocenjena raven se lahko dobi s prištevanjem popravkov k izmerjeni(-m) ali napovedani(-m) ravni(-em), da se
upoštevajo razlike med vrstami virov. Z upoštevanjem cestnega prometa kot osnovnega vira hrupa se lahko na
primer uporabijo popravki ravni za vire letalskega ali železniškega prometa.
3.4 Oznake zvoka
Opomba: Glej sliko 1.
3.4.1
celotni zvok
vseobsegajoči zvok v dani situaciji v danem času, navadno sestavljen iz zvoka, ki prihaja iz več bližnjih
in oddaljenih virov
SIST ISO 1996-1 : 2016
a) Trije obravnavani specifični zvoki A, B in C, preostali zvok in celotni zvok
b) Dva obravnavana specifična zvoka A in B, preostali zvok in celotni zvok
Legenda:
1 celotni zvok
2 specifični zvok A
3 specifični zvok B
4 specifični zvok C
5 preostali zvok
OPOMBA 1: Najnižja raven preostalega zvoka se doseže, ko so izločeni vsi specifični zvoki.
OPOMBA 2: Pikčasto območje označuje preostali zvok, ko so izločeni zvoki A, B in C.
OPOMBA 3: Na sliki 1 b) preostali zvok vključuje specifični zvok C, ker ni predmet obravnave.
Slika 1: Oznake za celotni, specifični in preostali zvok
3.4.2
specifični zvok
sestavni del celotnega zvoka, ki ga je mogoče posebej ugotoviti in ki je povezan s specifičnim virom
3.4.3
preostali zvok
celotni zvok, ki ostane na določenem mestu v dani situaciji, ko se izključijo obravnavani specifični zvoki
3.4.4
začetni zvok
celotni zvok, prisoten v začetni situaciji, pred kakršnokoli spremembo obstoječe situacije
SIST ISO 1996-1 : 2016
3.4.5
nihajoči zvok
neprekinjeni zvok, katerega raven zvočnega tlaka v obdobju opazovanja občutno niha, vendar ne v
impulznem smislu
3.4.6
intermitentni zvok
zvok, ki je prisoten pri opazovalcu le v določenih časovnih obdobjih in se pojavlja v rednih ali nerednih
časovnih intervalih in pri katerem trajanje vsakega takega pojavljanja traja več kot približno 5 s
PRIMER: Hrup motornih vozil pri manjšem prometu, hrup vlakov, hrup letal in zračnega kompresorja.
3.4.7
povečanje zvoka
povečanje celotnega zvoka v dani situaciji, ki nastane zaradi uvajanja določenega specifičnega zvoka
3.4.8
impulzni zvok
zvok, za katerega so značilni kratkotrajni izbruhi zvočnega tlaka
Opomba 1: Trajanje posamičnega impulznega zvoka je navadno krajše od 1 s.
3.4.9
tonalni zvok
zvok, za katerega je značilna ena frekvenčna komponenta ali ozkopasovne komponente, ki slišno
izstopajo iz celotnega zvoka
3.5 Viri impulznega zvoka
OPOMBA: V času objave tega dela ISO 1996 ne obstaja noben matematični kazalec, s katerim je mogoče nedvoumno
potrditi prisotnost impulznega zvoka ali pa razvrstiti impulzni zvok v kategorije, navedene v točkah od 3.5.1 do
3.5.3. Vendar je ugotovljeno, da te tri kategorije najbolje odražajo odziv skupnosti. Tako se viri hrupa, navedeni v
točkah od 3.5.1 do 3.5.3, uporabljajo za opredelitev virov impulznega zvoka.
3.5.1
vir visokoenergijskega impulznega zvoka
eksplozivni vir, katerega ekvivalentna masa TNT presega 50 g, ali vir s primerljivimi značilnostmi in
stopnjo motenja
Opomba 1: Med vire, ki povzročajo preboj zvočnega zidu, sodijo letala, rakete, topniški izstrelki, oklepni projektili in drugi
podobni viri. Ta kategorija ne vključuje kratkotrajnih prebojev zvočnega zidu, kot na primer nastajajo pri
malokalibrskem orožju in drugih podobnih virih.
PRIMER: Kamnolomske in rudarske eksplozije, nadzvočni udari, rušenje ali industrijski procesi, ki uporabljajo visoko
eksplozivna sredstva, eksplozivni industrijski lomilniki in vojaška ubojna sredstva (npr. orožje, topništvo,
minometni ogenj, bombe, eksplozivni vžig raket in projektilov).
3.5.2
visokoimpulzni vir zvoka
vir z visoko impulznimi značilnostmi in z visoko stopnjo motenja
PRIMER: Malokalibrsko orožje, udarci po kovini ali lesu, pištole za žeblje, udarno kladivo, zabijanje pilotov, strojno kovanje,
stiskalnice, pnevmatsko kovanje, rušilna kladiva ali udarci kovine pri ranžiranju v železniških operacijah.
3.5.3
navadni impulzni vir zvoka
impulzni vir zvoka, ki ni niti visokoimpulzni vir zvoka niti vir visokoenergijskega impulznega zvoka
Opomba 1: Ta kategorija vključuje zvoke, ki so včasih opisani kot impulzni, vendar se navadno ocenjuje, da niso tako moteči
kot visokoimpulzni zvoki.
SIST ISO 1996-1 : 2016
PRIMER: Loputanje z avtomobilskimi vrati, igre z žogo na prostem, kot sta nogomet ali košarka, in cerkveni zvonovi. Zelo
hitre nizke prelete vojaških letal je prav tako mogoče uvrstiti v to kategorijo.
3.6 Dnevne, večerne, nočne ravni zvoka
3.6.1
dnevna raven zvoka
L
dan,h
ekvivalentna neprekinjena raven zvočnega tlaka, ko je referenčni časovni interval dan
Opomba 1: Podpisana oznaka h pomeni število ur, npr. L .
dan,12
Opomba 2: Navadno je dan 12 ur med 7. in 19. uro ali 15 ur med 7. in 22. uro, vendar posamezne države dan opredeljujejo
drugače, npr. od 6. do 18. ure ali od 6. do 22. ure.
3.6.2
večerna raven zvoka
L
večer,h
ekvivalentna neprekinjena raven zvočnega tlaka, ko je referenčni časovni interval večer
Opomba 1: Podpisana oznaka h pomeni število ur, npr. L .
večer,4
Opomba 2: Navadno je večer 4 ure med 19. in 23. uro, vendar posamezne države večer opredeljujejo drugače, npr. od 18.
do 22. ure.
3.6.3
nočna raven zvoka
L
noč,h
ekvivalentna neprekinjena raven zvočnega tlaka, ko je referenčni časovni interval noč
Opomba 1: Podpisana oznaka h pomeni število ur, npr. L .
noč,8
Opomba 2: Navadno je noč 8 ur med 23. in 7. uro ali 9 ur med 22. in 7. uro, vendar posamezne države noč opredeljujejo
drugače, npr. od 22. do 6. ure.
3.6.4
dnevno-večerno-nočna raven zvoka
L
dvn
dnevno-večerno-nočno-vrednotena raven zvoka je določena z enačbo:
kjer so t , t in t izraženi v urah in velja t + t + t = 24 h.
dan večer noč dan večer noč
Opomba 1: Privzete vrednosti za tdan, tvečer in tnoč so 12 h, 4 h in 8 h, vendar posamezne države, npr. države članice EU,
skrajšujejo večerno obdobje.
3.6.5
dnevno-nočna raven zvoka
L
dn
dnevno-nočno-vrednotena raven zvoka je določena z enačbo:
kjer sta t in t izražena v urah in velja t + t = 24 h.
dan noč dan noč
Opomba 1: Privzeti vrednosti za t in t sta 15 ur in 9 ur.
dan noč
SIST ISO 1996-1 : 2016
3.6.6
tolerančna raven skupnosti
L
ct
dnevno-nočna raven zvoka, pri kateri se predvideva, da bo 50 % ljudi v določeni skupnosti
izpostavljenost hrupu zelo motila
Opomba 1: L se uporablja kot parameter, ki upošteva razlike med viri in/ali skupnostmi pri napovedovanju odstotka ljudi, ki
ct
jih izpostavljenost hrupu zelo moti.
Opomba 2: Dodatek H vsebuje dodatne informacije o parametru L .
ct
4 Simboli
Simboli so podani v preglednici 1, kjer sta A-frekvenčno vrednotenje in F-časovno vrednotenje navedeni
samo zaradi boljše nazornosti (razen za L , kjer se navadno uporablja C-vrednotenje, čeprav bi se
Cpeak
lahko uporabilo tudi drugačno vrednotenje z izjemo A-vrednotenja). Po potrebi oziroma na zahtevo
pristojnih organov se lahko nadomestita z drugimi frekvenčnimi in časovnimi vrednotenji, kot jih določa
IEC 61672-1.
Preglednica 1: Simboli za zvočni tlak in ekspozicijske ravni zvoka
Veličina Simbol
Časovno in frekvenčno vrednotena raven zvočnega tlaka L
pAF
Maksimalna raven časovno in frekvenčno vrednotenega zvočnega tlaka LAFmax
Percentilna raven LAFNT
L
Vršna raven zvočnega tlaka Cpeak
Ekspozicijska raven zvoka L
EA
Ekvivalentna neprekinjena raven zvočnega tlaka LAeq,T
Ocenjena ekspozicijska raven zvoka LRE
Ocenjena ekvivalentna neprekinjena raven L
Req,T
5 Kazalci (deskriptorji) hrupa v okolju
5.1 Posamični dogodki
5.1.1 Kazalci (deskriptorji)
Zvoki posamičnih dogodkov (kot so mimovoz tovornjaka, prelet letala ali eksplozija v kamnolomu) so
primeri posamičnih zvočnih dogodkov. Posamični zvočni dogodek je mogoče označiti z več kazalci. Ti
kazalci vključujejo fizikalne veličine in ustrezne ravni v decibelih. Pogosto se uporabljajo trije kazalci za
opisovanje zvoka posamičnih dogodkov. Uporablja se A-frekvenčno vrednotenje, razen za
visokoenergijski impulzivni zvok in zvok z občutnim nizkofrekvenčnim deležem. Priporočajo se trije
kazalci:
a) ekspozicijska raven zvoka z določenim frekvenčnim vrednotenjem,
b) maksimalna raven zvočnega tlaka z določenim časovnim in frekvenčnim vrednotenjem,
c) vršna raven zvočnega tlaka z določenim frekvenčnim vrednotenjem.
Uporaba A-vrednotenih vršnih ravni zvočnega tlaka ni priporočljiva (glej točko 4).
SIST ISO 1996-1 : 2016
5.1.2 Trajanje dogodka
Trajanje dogodka je treba določiti glede na značilnosti zvoka, kot je število preseganj točno določene
ravni.
PRIMER: Trajanje zvočnega dogodka je mogoče opredeliti kot celotni čas, ko je raven zvočnega tlaka za do manj kot 10 dB
nižja od njegove maksimalne ravni zvočnega tlaka.
OPOMBA: Medtem ko ekspozicijska raven zvoka združuje raven zvoka in njegovo trajanje, je mogoče koncept trajanja
dogodka uporabiti pri razlikovanju dogodkov. Prelet letala lahko na primer traja od 10 do 20 s, medtem ko je
trajanje strela manj kot 1 s.
5.2 Ponavljajoči se posamični dogodki
Ponavljajoči se posamični dogodki okoljskega zvoka so navadno ponovitve posamičnega zvočnega
dogodka. Hrup letalskega, železniškega ali cestnega prometa z majhno gostoto prometa je na primer
mogoče obravnavati kot seštevek zvokov iz več posameznih dogodkov. Tudi zvok streljanja je seštevek
zvokov več posameznih zvokov strelov. V tem delu ISO 1996 se za opis vseh ponavljajočih se virov
posamičnih dogodkov zvoka uporabljajo ekspozicijske ravni zvoka posamičnih dogodkov in ustrezno
število dogodkov za določitev ocenjene ekvivalentne neprekinjene ravni zvočnega tlaka.
5.3 Neprekinjeni zvok
Transformatorji, ventilatorji in hladilni stolpi so primeri virov neprekinjenega zvoka. Raven zvočnega
tlaka zvoka iz vira neprekinjenega zvoka je lahko stalna, nihajoča ali počasi spremenljiva v časovnem
intervalu. Neprekinjeni zvok je najbolje opisan z A-vrednoteno ekvivalentno neprekinjeno ravnjo
zvočnega tlaka v določenem časovnem intervalu. Za nihajoči zvok in intermitentni zvok je mogoče
uporabiti tudi A-vrednoteno maksimalno raven zvočnega tlaka z določenim časovnim vrednotenjem.
OPOMBA: Odvisno od situacije je mogoče hrup cestnega prometa opredeliti kot vir neprekinjenega zvoka ali kot seštevek
številnih ponavljajočih se posamičnih zvočnih dogodkov.
6 Vznemirjenost zaradi hrupa
6.1 Kazalci (deskriptorji) hrupa v življenjskem okolju
Ta del ISO 1996 daje napotke za ocenjevanje hrupa v okolju iz posameznih virov ali kakršnekoli
kombinacije virov. Pristojni organi se lahko odločijo, kateri viri, če sploh, se kombinirajo, in kateri
popravki, če sploh, se upoštevajo. Če ima zvok specifične značilnosti, mora biti primarni kazalec za
opisovanje zvoka ocenjena ekvivalentna neprekinjena raven zvočnega tlaka. Določijo se lahko tudi drugi
kazalci, kot je maksimalna raven zvočnega tlaka, (popravljena) ekspozicijska raven zvoka ali vršna
raven zvočnega tlaka.
Raziskave so pokazale, da samo A-frekvenčno vrednotenje ne zadostuje za oceno zvokov z značilno
tonaliteto, impulznostjo ali močno zastopanostjo nizkofrekvenčnih komponent. Za oceno dolgoročnega
odziva skupnosti na vznemirjenost zaradi zvokov z nekaterimi od teh specifičnih značilnosti se dodaja
popravek v decibelih k A-vrednoteni ekspozicijski ravni zvoka ali k A-vrednoteni ekvivalentni neprekinjeni
ravni zvočnega tlaka. Raziskave so pokazale tudi, da zvoki različnih prevoznih sredstev ali industrijski
zvoki različno vznemirjajo skupnost pri sicer enaki A-vrednoteni ekvivalentni neprekinjeni ravni
zvočnega tlaka. V poglavju Literatura je naveden seznam poročil in publikacij, ki opisujejo tehnične
osnove metod ocenjevanja in napovedi po tem delu ISO 1996.
6.2 Frekvenčno vrednotenje
A-frekvenčno vrednotenje se na splošno uporablja za oceno vseh virov zvoka, razen visokoenergijskih
impulznih zvokov in zvokov z močno zastopanostjo nizkofrekvenčnih komponent. A-frekvenčno
vrednotenje se ne sme uporabljati za merjenje vršne ravni zvočnega tlaka.
SIST ISO 1996-1 : 2016
6.3 Popravljene ravni
6.3.1 Popravljene ekspozicijske ravni zvoka
Kadar je ekspozicijske ravni zvoka posamičnih dogodkov mogoče izmeriti ali izračunati ločeno, je treba
uporabiti naslednjo metodo. Če pa pri merjenju ni mogoče ločiti zvoka posamičnega dogodka od drugih
virov, je treba uporabiti metodo, opisano v točki 6.3.2.
Za vsak posamični zvočni dogodek, razen za visokoenergijske impulzne zvoke ali zvoke z močno
zastopanostjo nizkofrekvenčnih komponent, se popravljena ekspozicijska raven zvoka L dobi s
REij
prištevanjem popravka ravni K za j-ti tip zvoka v decibelih k ekspozicijski ravni zvoka L za i-ti zvok
j Eij
posamičnega dogodka. Napotki za popravke specifičnih kategorij virov hrupa in za specifične razmere
so navedeni v dodatkih A, B, E in F.
V matematičnem zapisu:
OPOMBA: Ta izdaja tega dela standarda ISO 1996 v točki 3.6.6 uvaja koncept tolerančne ravni skupnosti L ; glej referenci
ct
[7] in [18] za boljše razumevanje in oceno prevalence vznemirjenosti zaradi hrupa v skupnostih. Tolerančna raven
skupnosti je pojasnjena v dodatku H. Dodatek E zagotavlja enoten niz popravkov za dnevno-večerno-nočno raven
zvoka L in dnevno-nočno raven zvoka L , ki neposredno izhajajo iz uporabe L . Dodatek F zagotavlja enoten
dvn dn ct
niz popravkov za L in L , ki posredno izhajajo iz razlik med prevalenco funkcij vznemirjenosti, ki se ločeno
dvn dn
nanašajo na tri kategorije virov hrupa zaradi prometa z uporabo regresijskega pristopa iz reference [15]. Pričakuje
se, da bodo države prevzele popravke bodisi iz dodatka E bodisi dodatka F.
6.3.2 Popravljena ekvivalentna neprekinjena raven zvočnega tlaka
V časovnem intervalu T je popravljena ekvivalentna neprekinjena raven zvočnega tlaka ali ocenjena
n
raven L za j-ti vir dejansko podana z ekvivalentno neprekinjeno ravnjo zvočnega tlaka L , z
Reqj,Tn Aeqj,Tn
dodanim popravkom K za j-ti vir, izraženim v decibelih. Napotki za popravke specifičnih kategorij virov
j
hrupa in za specifične razmere so navedeni v dodatkih A, E in F.
V matematičnem zapisu:
Popravke, ki se nanašajo na značilnosti zvoka, je treba uporabiti le v času prisotnosti določene
značilnosti. Če je na primer zvok po značilnosti tonalen, je treba popravke uporabljati samo, ko je tonalen
zvok zaznaven.
6.4 Ocenjevanje ravni
6.4.1 En vir zvoka
Če je v časovnem intervalu T pomemben le en vir zvoka, je ocenjena raven enaka ekvivalentni
n
neprekinjeni ravni zvočnega tlaka, izračunani z enačbo (3) iz popravljene ekspozicijske ravni zvoka,
podane v točki 6.3.1, ali pa je popravljena ekvivalentna neprekinjena raven zvočnega tlaka podana v
točki 6.3.2. Ocenjene ravni je mogoče razviti za katerikoli časovni interval, določen v točki 3.2.
kjer je t = 1 s.
o
SIST ISO 1996-1 : 2016
6.4.2 Kombinirani viri
Splošni napotki za ocenjevanje ocenjenih ravni kombiniranih virov so podani v dodatku G. Ocenjene
ravni kombiniranih virov je mogoče razviti za katerikoli časovni interval, določen v točki 3.2. Na splošno
se časovni interval T razdeli na časovne intervale T za vsak vir j. Vrednost T je izbrana tako, da je
nj nj
popravek L konstanten. Razdelitev T je lahko različna za različne vire. Ocenjena ekvivalentna
Req,jTnj
neprekinjena raven zvočnega tlaka je podana z enačbo:
kjer je:
za vsak vir j.
OPOMBA: V praksi se z enačbo (4) navadno ovrednoti en vir naenkrat.
6.5 Sestavljene celodnevne ravni
Pogosto uporabljena druga metoda za opis hrupa v življenjskem okolju je metoda z oceno celodnevne
sestavljene ocenjene ravni iz ocenjenih ravni v različnih obdobjih enega celega dne. Ocenjena dnevno-
nočna raven L je na primer dana z enačbo:
Rdn
kjer so:
d število ur v dnevu
L ocenjena raven za dnevni čas, vključno s popravki za vire zvoka in zvočne značilnosti
Rd
L ocenjena raven za nočni čas, vključno s popravki za vire zvoka in zvočne značilnosti
Rn
K popravek za dnevni čas
d
K popravek za nočni čas
n
Podobno enačbo je mogoče uporabiti za vpeljavo ocenjene dnevno-večerne-nočne ravni L :
Rdvn
kjer so:
e število ur večera
L ocenjena raven za večerni čas, vključno s popravki za vire zvoka in zvočne značilnosti
Rv
K popravek za večerni čas
v
druge oznake pa so enake tistim z enačbi (5)
Pristojni organi naj bi določili trajanje dneva in ur, ki zajemajo dan.
SIST ISO 1996-1 : 2016
Če pravni sistem vključuje popravke ob koncu tedna, je treba ocenjeno raven izračunati ločeno za
delavnike, sobote in nedelje. Za prikaz celotnega časovnega obdobja naj letno povprečje vključuje
pravilen delež delavnikov, sobot in nedelj.
7 Zahteve za omejitve hrupa
7.1 Splošno
Omejitve hrupa določijo pristojni organi na podlagi poznavanja učinkov hrupa na človekovo zdravje in
dobro počutje (zlasti odnosa med dozo in učinkom na vznemirjenost) ob upoštevanju socialnih in
gospodarskih dejavnikov.
Takšne omejitve so odvisne od mnogih dejavnikov, kot so obdobje dneva (npr. dan, večer, noč in 24 h),
dejavnosti, ki jih je treba varovati (npr. življenje na prostem ali v zaprtih prostorih, komunikacija v šolah,
rekreacija v parkih), tip vira zvoka in razmere (npr. razvoj novih stanovanjskih območij v obstoječih
razmerah, novi industrijski ali prometni objekti v bližini obstoječih stanovanjskih območij in sanacijski
ukrepi v obstoječih razmerah).
Predpisi za omejitve hrupa vključujejo mejne vrednosti in postopke, ki opisujejo okoliščine, v katerih je
mogoče preveriti skladnost s predpisi. Ti postopki lahko temeljijo na modelnih izračunih za napoved
hrupa ali na meritvah.
Postopek mora vsebovati naslednje elemente:
a) enega ali več kazalcev zvoka,
b) ustrezne časovne intervale,
c) vir in način njegovega delovanja ter njegovo okolje,
d) lokacijo(-e), kjer se preverjajo omejitve hrupa,
e) razmere pri širjenju od vira do sprejemnika,
f) metodo za upoštevanje negotovosti v napovedi ali pri merilnem postopku,
g) tip in značilnosti območja, kjer se bodo uporabljale omejitve hrupa,
h) merila za ocenjevanje skladnosti z omejitvami.
7.2 Specifikacije
7.2.1 Kazalci (deskriptorji) hrupa
Najpriporočljivejši kazalec za podajanje omejitev hrupa je ocenjena raven v enem ali več določenih
referenčnih časovnih intervalih. Pri uporabi ocenjenih ravni je treba navesti popravke, ki morajo biti
upoštevani.
V nekaterih državah se razlike v oceni virov zvoka ne upoštevajo na podlagi popravkov, temveč na
podlagi omejitev za specifične vire. Omejitve, ki veljajo za zvočne dogodke, je mogoče določiti na osnovi
ekspozicijske ravni zvoka ali maksimalne ravni. V obeh primerih naj bi se navedla (statistična) vrednost,
na katero se omejitev nanaša (npr. maksimalna raven v določenem časovnem intervalu in srednja
vrednost maksimalnih ravni za najglasnejšo kategorijo navedenega vira).
Če so določene dodatne omejitve glede drugih kazalcev, kot je povečanje zvoka, je treba določiti
postopke za določanje teh vrednosti.
7.2.2 Relevantni časovni intervali
Določijo se referenčni časovni intervali, na katere se nanaša ocena. Ti morajo biti povezani s tipičnimi
človeškimi dejavnostmi in spremembami v delovanju vira zvoka.
SIST ISO 1996-1 : 2016
Jasno mora biti navedeno, katere spremembe zvočnih emisij in prehodov (transmisij) zvoka je treba
upoštevati v referenčnih časovnih intervalih pri preverjanju skladnosti z omejitvami.
Dodatno morajo biti navedeni dolgotrajni časovni intervali (glej 3.2.2).
7.2.3 Viri zvoka in njihove obratovalne razmere
Viri, za katere veljajo omejitve hrupa, morajo biti navedeni. Kadar je to primerno, je treba navesti tudi
obratovalne razmere vira.
7.2.4 Lokacije
Lokacije, na katerih morajo biti upoštevane omejitve hrupa, je treba jasno določiti. Če je treba omejitve
preveriti z meritvami v bližini stavb ali drugih velikih odbojnih objektov, naj se upoštevajo napotki,
navedeni v ISO 1996-2.
7.2.5 Pogoji za širjenje
Pri prenosu zvoka na prostem obstaja možnost, da spremembe vremenskih razmer vplivajo na raven
zvočnega tlaka. V takšnih primerih morajo mejne vrednosti hrupa temeljiti na povprečni vrednosti, bodisi
za vse relevantne pogoje širjenja ali z
...
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