SIST EN ISO 11690-1:2021
(Main)Acoustics - Recommended practice for the design of low-noise workplaces containing machinery - Part 1: Noise control strategies (ISO 11690-1:2020)
Acoustics - Recommended practice for the design of low-noise workplaces containing machinery - Part 1: Noise control strategies (ISO 11690-1:2020)
This document outlines strategies to be used in dealing with noise problems in existing and planned workplaces by describing basic concepts in noise control (noise reduction, noise emission, noise immission and noise exposure). It is applicable to all types of workplaces and all types of sources of sound which are met in workplaces, including human activities.
It includes those important strategies to adopt when buying a new machine or equipment.
This document deals only with audible sound.
Akustik - Richtlinien für die Gestaltung lärmarmer maschinenbestückter Arbeitsstätten - Teil 1: Allgemeine Grundlagen (ISO 11690-1:2020)
Ausgehend von der Beschreibung der grundlegenden Konzepte des Schallschutzes (Lärmminderung, Geräuschemission, Geräuschimmission und Geräuschexposition), beschreibt dieses Dokument Strategien für die Behandlung von Lärmproblemen in bestehenden und geplanten Arbeitsstätten. Es ist anwendbar auf alle Arten von Arbeitsstätten und alle Arten von Schall, die in Arbeitsräumen vorkommen können, wobei auch menschliche Tätigkeiten eingeschlossen sind.
Sie enthält wichtige Hinweise, die beim Kauf einer neuen Maschine oder Anlage anzuwenden sind.
Dieses Dokument befasst sich ausschließlich mit Hörschall.
Acoustique - Pratique recommandée pour la conception de lieux de travail à bruit réduit contenant des machines - Partie 1: Stratégies de maîtrise du bruit (ISO 11690-1:2020)
Le présent document présente les stratégies à mettre en œuvre pour traiter les problèmes de bruit sur les lieux de travail existants ou en projet, en s'appuyant sur des concepts de base liés à la maîtrise du bruit (maîtrise du bruit, émission sonore, bruit ambiant et exposition au bruit). Il s'applique à tous les types de lieux de travail et de sources de bruit rencontrées sur les lieux de travail, activités humaines comprises.
Il inclut les stratégies importantes à adopter lors de l'achat d'une nouvelle machine ou d'un nouvel équipement.
Le présent document ne traite que des sons audibles.
Akustika - Priporočena praksa za oblikovanje tihih delovnih mest - 1. del: Strategija obvladovanja hrupa (ISO 11690-1:2020)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-marec-2021
Nadomešča:
SIST EN ISO 11690-1:1997
Akustika - Priporočena praksa za oblikovanje tihih delovnih mest - 1. del:
Strategija obvladovanja hrupa (ISO 11690-1:2020)
Acoustics - Recommended practice for the design of low-noise workplaces containing
machinery - Part 1: Noise control strategies (ISO 11690-1:2020)
Akustik - Richtlinien für die Gestaltung lärmarmer maschinenbestückter Arbeitsstätten -
Teil 1: Allgemeine Grundlagen (ISO 11690-1:2020)
Acoustique - Pratique recommandée pour la conception de lieux de travail à bruit réduit
contenant des machines - Partie 1: Stratégies de maîtrise du bruit (ISO 11690-1:2020)
Ta slovenski standard je istoveten z: EN ISO 11690-1:2020
ICS:
13.140 Vpliv hrupa na ljudi Noise with respect to human
beings
17.140.20 Emisija hrupa naprav in Noise emitted by machines
opreme and equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 11690-1
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2020
EUROPÄISCHE NORM
ICS 13.140 Supersedes EN ISO 11690-1:1996
English Version
Acoustics - Recommended practice for the design of low-
noise workplaces containing machinery - Part 1: Noise
control strategies (ISO 11690-1:2020)
Acoustique - Pratique recommandée pour la Akustik - Richtlinien für die Gestaltung lärmarmer
conception de lieux de travail à bruit réduit contenant maschinenbestückter Arbeitsstätten - Teil 1:
des machines - Partie 1: Stratégies de maîtrise du bruit Allgemeine Grundlagen (ISO 11690-1:2020)
(ISO 11690-1:2020)
This European Standard was approved by CEN on 17 October 2020.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11690-1:2020 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 11690-1:2020) has been prepared by Technical Committee ISO/TC 43
"Acoustics" in collaboration with Technical Committee CEN/TC 211 “Acoustics” the secretariat of which
is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2021, and conflicting national standards shall be
withdrawn at the latest by May 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 11690-1:1996.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 11690-1:2020 has been approved by CEN as EN ISO 11690-1:2020 without any
modification.
INTERNATIONAL ISO
STANDARD 11690-1
Second edition
2020-10
Acoustics — Recommended practice
for the design of low-noise workplaces
containing machinery —
Part 1:
Noise control strategies
Acoustique — Pratique recommandée pour la conception de lieux de
travail à bruit réduit contenant des machines —
Partie 1: Stratégies de maîtrise du bruit
Reference number
ISO 11690-1:2020(E)
©
ISO 2020
ISO 11690-1:2020(E)
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
ISO 11690-1:2020(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General noise descriptors . 1
3.2 Noise emission descriptors . 2
3.3 Noise immission and noise exposure . 4
3.4 Noise reduction . 6
4 Basic concepts in noise control .11
4.1 Basic noise control strategy .11
4.2 Concept of noise reduction .11
5 Assessment of the noise situation .12
5.1 Quantities for noise emission, noise immission and noise exposure .12
5.1.1 Noise emission quantities [see 3.2 and Figure 1 a)] .12
5.1.2 Noise immission and noise exposure quantities [see 3.3 and Figures 1 b),
1 c) and 2] .12
5.2 Description of the noise situation .13
5.3 Use of noise information sheets and noise maps .14
6 Parties involved .15
7 How to tackle noise problems in workplaces .15
7.1 Noise control objectives .15
7.2 Principles of noise control planning for new and existing workplaces .16
7.2.1 General.16
7.2.2 Preliminary planning and design stage .17
7.2.3 Planning and design stage .17
7.2.4 Implementation stage.18
7.2.5 Assessment and acceptance stage .19
7.3 Dealing with existing noise problems .19
8 What to do before buying a new machine .19
8.1 Questions that a potential buyer should consider .19
8.2 What information to request from potential suppliers .20
8.3 Declared and additional noise emission values . .22
8.4 Meaning and use of noise emission values .22
8.5 Requirements for noise immission levels .23
8.6 Verification of declared noise emission and/or noise immission levels .23
8.7 Developments .23
9 Noise prediction as a planning tool.24
10 Long-term noise control programme .24
Bibliography .27
ISO 11690-1:2020(E)
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 of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise,
in collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/
TC 211, Acoustics, in accordance with the Agreement on technical cooperation between ISO and CEN
(Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 11690-1:1996), of which it constitutes a
minor revision. The changes compared to the previous edition are editorial.
A list of all parts in the ISO 11690 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved
ISO 11690-1:2020(E)
Introduction
Several standards specify methods for measurement and/or evaluation of noise. The final objective of
the ISO 11690 series is noise reduction.
A number of noise control measures are offered. However, in order to be effective, the most appropriate
noise control measure(s) should be chosen for a given situation.
It is important when non-acoustic engineers are involved in noise control practice for these engineers
to have a basic knowledge of noise emission and propagation characteristics and to understand the
basic principles of noise control.
To assist in the development of noise control in the workplace, it is essential that the information
contained in these recommended practices is disseminated through International Standards.
In order to reduce noise as a hazard in the workplace, individual countries have produced national
legislation. Generally, such national legislation requires noise control measures to be carried out in
order to achieve the lowest reasonable levels of noise emission, noise immission and noise exposure,
taking into account:
— known available measures;
— the state of the art regarding technical progress;
— the treatment of noise at source;
— appropriate planning, procurement and installation of machines and equipment.
This part of ISO 11690, together with the two other parts in the series, outlines procedures to be
considered when dealing with noise control at workplaces, within workrooms and in the open. These
recommended practices give in relatively simple terms the basic information necessary for all parties
involved in noise control in workplaces and in the design of low-noise workplaces to promote the
understanding of the desired noise control requirements.
The purpose of the ISO 11690 series is to bridge the gap between existing literature on noise control and
the practical implementation of noise control measures. In principle, the series applies to all workplaces
and its main function is:
— to provide simple, brief information on some aspects of noise control in workplaces;
— to act as a guide to help in the understanding of requirements in standards, directives, text books,
manuals, reports and other specialized technical documents;
— to provide assistance in decision making when assessing the various measures available.
The ISO 11690 series should be useful to persons such as plant personnel, health and safety officers,
engineers, managers, staff in planning and purchasing departments, architects and suppliers of plants,
machines and equipment. However, the above-mentioned parties should keep in mind that adherence
to the recommendations of the ISO 11690 series is not all that is necessary to create a safe workplace.
The effects of noise on health, well-being and human activity are many. By giving guidelines for noise
control strategies and measures, the ISO 11690 series aims at a reduction of the impact of noise on
human beings at workplaces. Assessment of the impact of noise on human beings is dealt with in other
documents.
INTERNATIONAL STANDARD ISO 11690-1:2020(E)
Acoustics — Recommended practice for the design of low-
noise workplaces containing machinery —
Part 1:
Noise control strategies
1 Scope
This document outlines strategies to be used in dealing with noise problems in existing and planned
workplaces by describing basic concepts in noise control (noise reduction, noise emission, noise
immission and noise exposure). It is applicable to all types of workplaces and all types of sources of
sound which are met in workplaces, including human activities.
It includes those important strategies to adopt when buying a new machine or equipment.
This document deals only with audible sound.
2 Normative references
The following documents are referred to in the text in such way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 4871, Acoustics — Declaration and verification of noise emission values of machinery and equipment
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1 General noise descriptors
3.1.1
sound pressure level
L
p
ten times the logarithm to the base 10 of the ratio of the mean-square sound pressure p, in pascals, to
the square of a reference value, p
p
L =10lg dB
p
2
p
where the reference value, p , is 20 µPa
Note 1 to entry: The sound pressure level is the main quantity to describe the noise at a given point. It is expressed
in decibels and should be measured with a standardized sound level meter (see IEC 61672-1).
Note 2 to entry: The frequency weighting (A or C) or the width of the frequency band and the time weighting
(S [slow], F [fast], I [impulse] or peak) used should be indicated.
ISO 11690-1:2020(E)
Note 3 to entry: For example, the C-weighted sound pressure level with time weighting peak is L .
pC,peak
Note 4 to entry: The notation L is used whether the sound pressure level refers to emission (see 3.2), immission
p
or exposure (see 3.3).
3.1.2
equivalent continuous sound pressure level
L
peq,T
sound pressure level of a continuous steady sound that within a measurement time interval, T, has the
same mean square sound pressure as a sound under consideration which varies with time, and is the
level of the mean square sound pressure over a time interval
T
01, Lt()
p
L =10lg 10 ddt B
pTeq, ∫
T
0
Note 1 to entry: Equivalent continuous sound pressure level is expressed in decibels.
Note 2 to entry: The equivalent continuous sound pressure level is the main quantity to assess the immission at
work stations and the exposure of persons.
Note 3 to entry: When immission or exposure is considered, impulse and tone adjustments, DL and DL , in
I T
decibels, may be used to take into account the influence of impulsive and tonal components (L + DL + DL )
pA,eq,T I T
(see ISO 1996-1, ISO 1996-2 and ISO 1999).
Note 4 to entry: Subscript “eq,T” is often omitted because in all cases considered in this document the sound
pressure is determined over a certain measurement time interval (see IEC 61672-1).
3.1.3
work station
position, in the vicinity of a machine, which can be occupied by the operator or a position where a task
is carried out
3.2 Noise emission descriptors
3.2.1
noise emission
airborne sound radiated into the environment from a defined source (machine or equipment)
[see Figure 1 a)]
3.2.2
sound power level
L
W
ten times the logarithm to the base 10 of the ratio of the sound power P, in watts, radiated by the sound
source under test to the reference sound power P = 1 pW
Note 1 to entry: Sound power level is expressed in decibels and is a descriptor of the emission of a sound source
(see the ISO 3740 and ISO 9614 series). The frequency weighting or the width of the frequency band used should
be indicated.
Note 2 to entry: For example, the A-weighted sound power level is L .
WA
3.2.3
emission sound pressure level
L
p
sound pressure level caused by a sound source under test at its work station or at any other specified
position
Note 1 to entry: Emission sound pressure level is expressed in decibels (dB) and is an additional descriptor of the
emission of a sound source (see ISO 11200 to ISO 11204).
2 © ISO 2020 – All rights reserved
ISO 11690-1:2020(E)
Note 2 to entry: The frequency weighting and/or the time weighting or the width of the frequency band used
shall be indicated.
Note 3 to entry: For example, the C-weighted peak emission sound pressure level is L .
pC,peak
Note 4 to entry: The A-weighted emission sound pressure level is often averaged over an operational period of a
sound source; it is denoted L .
pA
3.2.4
surface sound pressure level
L
pA,d
A-weighted sound pressure level averaged on an energy basis over a measurement surface at a distance
d from the sound source
Note 1 to entry: When d = 1 m, it is usually noted L .
pA,1m
3.2.5
measured noise emission value
L
any of the A-weighted sound power level, the A-weighted time-averaged emission sound pressure level,
or the C-weighted peak emission sound pressure level, determined from measurements
Note 1 to entry: Measured values may be determined either for a single machine or from the average of a number
of machines.
Note 2 to entry: Measured noise emission value is expressed in decibels and is not rounded.
3.2.6
noise emission declaration
information on the noise emitted by the machine, given by the manufacturer or the supplier in technical
documents or other literature, concerning noise emission values
Note 1 to entry: The noise emission declaration may take the form of either the declared single-number noise
emission value or the declared dual-number noise emission value.
3.2.7
uncertainty
K
value of the measurement uncertainty associated with a measured noise emission value
Note 1 to entry: Uncertainty is expressed in decibels and is not rounded.
3.2.8
declared single-number noise emission value
L
d
sum of a measured noise emission value, L, and the associated uncertainty, K, rounded to the nearest
decibel (dB)
L = L + K
d
3.2.9
declared dual-number noise emission value
L and K
measured noise emission value, L, and its associated uncertainty, K, both rounded to the nearest decibel
ISO 11690-1:2020(E)
3.3 Noise immission and noise exposure
3.3.1
noise immission at a work station
all noises that arrive, whether or not a worker is present, over a specific time period T, at a measuring
point (work station) in the actual situation; i.e. noise coming from the machine, noise coming from the
other sound sources and noise reflected by the ceiling, the walls and any fittings [see Figure 1 b)]
Note 1 to entry: T can be the duration of a measurement, an operating cycle of a machine, a process, the duration
a worker is usually present at or near the measurement point, or the duration of the workshift.
3.3.2
noise exposure of a person
all noises that arrive, over a specific time period T, at a person’s ear in the actual situation [see Figure 1 c)
and Figure 2]
3.3.3
noise immission and noise exposure descriptors
equivalent continuous A-weighted sound pressure level normalized to a nominal working day, L
pTAe,,q
in decibels
LL=+10lg TT/ dB
()
pTAe,,qApT,,eq e 0
0 e
where T is the reference duration (e.g. 8 h) and T is the duration of the workshift
0 e
Note 1 to entry: Immission is measured at the work station. Exposure is measured at the ear of the person.
Note 2 to entry: L can result from the energetic summation of immission or exposure values, L ,
pTAe,,q pTAe,,q
0 i
measured over individual time periods T , with ∑=TT .
i
i e
Note 3 to entry: In some countries, a rating level L is used:
pAr,
LL=+DL +DL dB
ppAr,,AeqI,T T
where DL and DL describe impulsive and tonal components.
I T
4 © ISO 2020 – All rights reserved
ISO 11690-1:2020(E)
a) Noise emission; sound radiation of a machine:
— machine related
— specified operating conditions
— independent of environment
b) Noise immission: sound impact at the work
station:
— work station related
— real operation
— dependendent on immission time
— contribution from all sound sources
c) Noise exposure; sound impact on human beings:
— person related [at one or several work stations
or for a person moving around (see Figure 2)]
— real operation
— dependent on exposure time
— contribution from all sound sources
Figure 1 — Illustration of the difference between noise emission, noise immission and noise
exposure (see also Figure 2)
Figure 2 — Illustration of noise exposure for a person moving around
ISO 11690-1:2020(E)
3.4 Noise reduction
3.4.1
sound reduction index
R
descriptor of transmission loss defined as ten times the logarithm to the base 10 of the ratio of the sound
power incident on a test specimen to the sound transmitted through the test specimen (see Figure 3.)
Note 1 to entry: It is expressed in decibels and is frequency dependent.
Note 2 to entry: Methods for determining the insulation of walls, doors, ceilings and windows are described in
ISO 10140 (all parts) and in ISO 717-1.
Key
1 reflection
2 absorption
3 transmission
NOTE A proportion of the sound which is incident on a partition or wall is reflected, a proportion is
transformed into heat (i.e. is absorbed) and a proportion goes through the wall to the other side (i.e. is
transmitted). The sound insulation of the wall determines what proportion of the incident sound is transmitted.
Figure 3 — Illustration of reflection, absorption and transmission at a boundary
3.4.2
sound absorption coefficient
α
fraction of the acoustic energy absorbed when sound waves strike a surface
Note 1 to entry: The sound absorption coefficient is frequency dependent.
Note 2 to entry: A single number rating is given in ISO 11654.
3.4.3
equivalent absorption area
A
area, in square meters, obtained by summing the products α S
i i
AS=+αα SS+=. α
11 22
where
6 © ISO 2020 – All rights reserved
ISO 11690-1:2020(E)
α is the absorption coefficient of a partial area, S , of a room surface;
i i
S is the total room area =∑S ;
()
i
α
is the mean absorption coefficient of the room
3.4.4
insertion loss
D
i
difference in sound power level or emission sound pressure level with and without a noise control
device applied to a sound source
Note 1 to entry: Insertion loss is frequency dependent and is expressed in decibels.
Note 2 to entry: The A-weighted insertion loss is always related to a given source.
Note 3 to entry: The insertion loss is used to assess the acoustical performance of enclosures (see ISO 11546-1
and ISO 11546-2), screens (see ISO 10053 and ISO 11821) and silencers (see ISO 7235, ISO 11691 and ISO 11820).
3.4.5
reduction of sound pressure level at a work station
result of a set of noise reduction measures described by the difference in noise immission levels
Note 1 to entry: For example, L – L , where numeral 1 means before and numeral 2 means after
pA,eq,8h,1 pA,eq,8h,2
technical measures for reduction have been taken.
3.4.6
direct sound
sound which propagates directly from the source to the point of observation
Note 1 to entry: No reflection of sound is involved so it is not affected by the characteristics of the room in which
the source is located.
3.4.7
reflected sound
sound at any point in a room, resulting from reflections from room surfaces and fittings, and excluding
the direct sound
3.4.8
diffuse-field conditions
sound propagation in rooms or regions of rooms where the sound is reflected so often and uniformly
from all surfaces of the room and the fittings that the sound pressure level of the reflected sound is the
same at any point inside the region
3.4.9
non-diffuse-field conditions
sound propagation in rooms or regions of rooms where sound does not propagate uniformly in all
directions
Note 1 to entry: Non-diffuse-field conditions are the case if
— the ratio of any two dimensions out of the three is more than three, or
— the absorption of the surfaces of the room is notably non-uniformly distributed (e.g. a room with hard walls
and absorbent ceiling), or
— the absorption is high.
ISO 11690-1:2020(E)
3.4.10
reverberation time
T
time, in seconds, it takes for the sound pressure level in a room (originally in a steady state) to decrease
60 dB after the source is turned off (See Figure 4)
Note 1 to entry: The reverberation time is frequency dependent.
Note 2 to entry: It is useful for describing the acoustic properties of rooms with a diffuse sound field; room
volume must be taken into account.
3.4.11
spatial sound distribution curve
curve which shows how the sound pressure level from a reference sound source decreases when the
distance to the source increases
Note 1 to entry: Spatial sound distribution curves are frequency dependent and characterize the acoustic
properties of rooms. In some cases, several spatial sound distribution curves are necessary to characterize a room.
Note 2 to entry: From this curve and for a given range of distances from the source, two main quantities are
determined (see Figure 5):
— the rate of spatial decay per distance doubling (DL ), and
— the excess of sound pressure level (DL ).
f
Three distance ranges are normally of interest: near, middle and far regions. These two quantities (DL , DL ) are
2 f
useful for assessing the acoustic quality of a room.
8 © ISO 2020 – All rights reserved
ISO 11690-1:2020(E)
Key
X time, in s
Y sound pressure level, in dB
T reverberation time
Figure 4 — Idealized time history of sound pressure level after the sound source is turned off
3.4.12
rate of spatial decay of sound pressure levels per distance doubling
DL
amount, in decibels, by which the sound pressure level decreases over a given range of distances, when
the distance from the source is doubled (see Figure 5)
3.4.13
excess of sound pressure level
DL
f
average difference, in decibels, over a given distance range, between the spatial sound distribution
curve of the room and the spatial sound distribution curve for a free field (6 dB per distance doubling)
(see Figure 5)
ISO 11690-1:2020(E)
Key
X distance from source
Y sound pressure level, L , in dB
p
1 near region
2 middle region
3 far region
4 spatial sound distribution curve
5 without reflections (free field)
Figure 5 — Example of:
(i) a spatial sound distribution curve for a room and for the free field;
(ii) the three ranges of distances;
(iii) the determination of the spatial decay (DL); and
(iv) the excess (DL ) of sound pressure level
f
10 © ISO 2020 – All rights reserved
ISO 11690-1:2020(E)
4 Basic concepts in noise control
4.1 Basic noise control strategy
Effective noise reduction will only be achieved by dealing with the problem in a systematic manner.
Listed below is a series of steps that should be considered when formulating a noise control strategy
and implementing noise control measures for new and existing workplaces.
a) Determine objectives and establish criteria.
b) Carry out noise assessment by identifying:
— the areas concerned,
— the immission at work stations,
— the contributions of different noise sources to the immission at work stations,
— the exposure of persons,
— the emission of sources in order to rank them.
c) Consider noise control measures such as:
— noise control at source,
— noise control on the transmission path in the workplace,
— noise control at work stations.
d) Formulate a noise control programme.
e) Implement the appropriate measures.
f) Verify the noise reduction attained.
4.2 Concept of noise reduction
Noise control can be implemented using various technical measures (see ISO 11690-2) and there may
be several ways to solve a noise problem. These measures are noise reduction at source (e.g. machines,
working processes), noise reduction by increasing the attenuation of sound during its propagation
(e.g. using enclosures, screens, absorbing linings), noise reduction at specific positions (e.g. using
cabins).
Technical measures for noise control should be applied in order to implement the state of the art with
regard to noise control. For this purpose, it is necessary to compare and determine the effectiveness of
these measures. Acoustical quantities are used for this purpose. They describe the acoustical features
of the sound sources, the noise reduction attained in workplaces, and especially at work stations, when
sound sources are operating and some noise control measures have been implemented.
The connection between regulations, standards and the use of acoustical quantities to assess noise
control measures offered by the market is illustrated in Figure 6.
ISO 11690-1:2020(E)
Key
1 machinery
2 additional noise reduction measures
3 characteristic acoustic quantities
4 market
5 purchase, assessment, planning, design
6 regulations, standards
7 user of technical equipment
Figure 6 — Factors affecting noise control
If noise immission and noise exposure levels are low, all possible effects of noise on man are reduced.
Such effects include hazards to health and safety, for example impairment of hearing capacity, stress,
disturbance of speech communication and recognition of warning signals, disturbance of tasks
requiring high concentration and attentiveness.
5 Assessment of the noise situation
5.1 Quantities for noise emission, noise immission and noise exposure
5.1.1 Noise emission quantities [see 3.2 and Figure 1 a)]
An important characteristic emission quantity which is normally used is the A-weighted sound power
level (L ) under defined mounting and operating conditions.
WA
Another characteristic emission quantity is the A-weighted emission sound pressure level (L ) at a
pA
specified position for defined mounting and operating conditions and due to the machine only.
There are further noise emission quantities such as frequency band levels, the C-weighted peak
emission sound pressure level at the work station and the time history.
Basic methods for measuring and declaring noise emission values are given in the ISO 3740 series, the
ISO 9614 series, the ISO 11200 series and ISO 4871. Noise test codes specify, for families of machines and
equipment, mounting and operating conditions during the determination of noise emission quantities.
5.1.2 Noise immission and noise exposure quantities [see 3.3 and Figures 1 b), 1 c) and 2]
In contrast to the emission quantities which are intrinsic descriptors of machines as sound sources,
noise immission quantities describe the total sound impact on the work station, and noise exposure
quantities describe the impact on human beings.
Noise immission quantities are evaluated at a given work station and over a time period representative
of the daily (or weekly) activity at this work station. If several activities follow one another at a work
station, it may be necessary to evaluate a set of noise immission values at this work station.
12 © ISO 2020 – All rights reserved
ISO 11690-1:2020(E)
Since they are specific to a person who may daily (or weekly) occupy different work stations, noise
exposure quantities can be evaluated from the noise immission or exposure quantities and the time
spent at each of the work stations concerned.
Noise exposure quantities for a person who occupies a single work station are identical to the noise
immission quantities of that work station.
In general, values of L , L and L are compared to noise immission and exposure limits.
pA,eq,8h pA,r pC,peak
The measurement uncertainty should be added to these values prior to the comparison with limits.
5.2 Description of the noise situation
In order to describe the noise situation in defined areas of a workplace, indoors or outdoors, the
following steps are normally carried out:
a) determination of work stations and related immission quantities;
b) determination, for each person, of the work stations involved and the corresponding exposures;
c) determination of sound sources and related noise emission quantities.
These data can be listed on a noise information sheet such as that shown in Table 1 for industrial
workplaces. Noise maps can also be useful (see Figure 7).
Table 1 — An example of noise description of a workplace
A) List of work stations
Work Description of work station
Machine No. Noise immission Additional values
station (task, job function, machine operation,
(No. from C) values (e.g. L , DL )
pC,peak I
No. process, etc.)
…
B) List of persons
a
Work station 1 Work station 2
Noise exposure
Person No. (No. from A) (No. from A)
values
Duration Duration
…
C) List of equipment/machines
Machine Sound power Emission sound Operating
Description of machine
No. level pressure level condition
…
a
More columns can be added if there are more work stations.
ISO 11690-1:2020(E)
Values in decibels
a) Indication of noise levels at work stations
b) Indication of region of noise levels (colours are often used for such noise maps)
c) Equal noise level curves (here with 5 dB increments)
Key
up to 90 dB
from 90 dB to 100 dB
above 100 dB
Figure 7 — Different illustrations of noise maps for a given workplace
5.3 Use of noise information sheets and noise maps
Noise information sheets and noise maps can be used for a variety of purposes:
a) to assess noise immission at work stations;
b) to identify the location of high-noise areas and dominant sound sources;
c) to identify noisy areas where noise immission levels exceed relevant noise limits;
d) to show the actual noise situation at a specified time;
e) as important tools at the planning stage of a new workplace;
f) as an aid to assess the effect of changing a machine, a working process or a working layout;
g) to verify the effectiveness of measures taken or planned;
h) as an aid to setting up a long-term noise control programme;
i) as a tool for dialogue and coordination between the parties involved;
j) to inform the persons exposed about the noise situation;
14 © ISO 2020 – All rights reserved
ISO 11690-1:2020(E)
k) as an aid in the performing of audiometric programmes and to motivate workers to wear personal
hearing protectors.
6 Parties involved
Noise control measures may modify substantially the machine/operator environment. It is therefore
recommended that all interested parties be involved in any proposed control measures.
Representatives of various functions in the company may be involved: i.e. management, planners,
purchase department, health and safety committees, medical orderlies, maintenance, process and
production departments, technical staff, unions and, obviously, the workers involved. To ensure
effective participation by all parties concerned, prior and appropriate information and training are
often necessary.
The diagnosis of the noise problem, its study and the definition and implementation of noise control
measures are normally performed in collaboration with the parties concerned. In many situations,
the involvement of external parties such as health and safety and labour protection authorities,
specialists in acoustics and ergonomics, etc. is recommended. Such collaboration between the company
representatives and external parties ensures that all constraints specific to the project under study are
taken into account when choosing the noise control measures.
The success of noise control planning is dependent on active and committed inv
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.
Loading comments...