ASTM E1130-16(2021)
(Test Method)Standard Test Method for Objective Measurement of Speech Privacy in Open Plan Spaces Using Articulation Index
Standard Test Method for Objective Measurement of Speech Privacy in Open Plan Spaces Using Articulation Index
SIGNIFICANCE AND USE
5.1 The speech privacy between locations in an open plan space is determined by the degree to which intruding speech sounds exceed the ambient sound pressure levels at the listener's ear; a classic signal-to-noise ratio situation.
5.2 The sound pressure levels at the listener's ear from intruding speech depend upon:
5.2.1 The individual vocal effort and orientation of the talker,
5.2.2 The attenuation of speech signals due to distance or intervening barriers, and
5.2.3 The reinforcement of speech signals due to reflections from surfaces such as the ceiling, furniture panels, light fixtures, walls, or windows.
5.3 The ambient sound levels within a space often must be increased in order to mask intruding speech using an electronic sound masking system. However, in certain locations and in specific frequency ranges, the building mechanical, electrical and plumbing (MEP) equipment, and the heating, ventilating, or air conditioning equipment (HVAC) may increase ambient sound levels or add tonal noise components that may require mitigation before tuning the masking sound.
5.4 The primary purpose of this test method is to assess the speech privacy for an average speech spectrum using the standard Articulation Index method. This requires measurement of the relevant acoustical characteristics discussed in 5.2 and 5.3 for a pair of locations and calculation of the Articulation Index using an average speech spectrum. The average speech spectrum is for male talkers speaking with normal voice effort. In specific cases such as designated quiet work zones for ‘focused work’ where administrative measures have been taken to reduce speech levels, a ‘casual’ voice spectrum should be used to calculate speech privacy, whereas in designated group work zones for ‘collaborative work’ where lively discussion is expected, a ‘raised’ voice spectrum should be used to calculate speech privacy.
5.5 The Articulation Index ranges from a low value of 0.00, where speech is gener...
SCOPE
1.1 This test method describes a means of objectively assessing speech privacy between locations in open plan spaces. This test method relies upon acoustical measurements, published information on speech levels, and standard methods for assessing speech communication. This test method does not measure the performance of individual open plan components which affect speech privacy; but rather, it assesses the privacy which results from a particular configuration of components (1, 2).2
1.2 This test method is intended to be a field test for the assessment of speech privacy in actual open plan spaces. However, this test method could be used in mock-up spaces and in environments arranged to simulate an open plan space.
1.3 This test method is suitable for use in many open plan spaces including traditional open offices, focus areas, and collaboration spaces. In addition to office buildings, these types of spaces will also be found in healthcare buildings, institutional spaces, schools, etc. It is not directly applicable for measuring the speech privacy between open plan and enclosed spaces or between fully enclosed spaces.
1.4 This test method relies upon the Articulation Index, which objectively predicts the intelligibility of speech. While both the Articulation Index and this test method can be expected to reliably predict speech privacy, neither predicts the specific effective speech privacy afforded to particular individual occupants.
1.5 The values stated in SI units are to be regarded as the standard. The inch-pound units in parentheses are for information only.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.7 This international standard was developed...
General Information
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Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E1130 − 16 (Reapproved 2021)
Standard Test Method for
Objective Measurement of Speech Privacy in Open Plan
Spaces Using Articulation Index
This standard is issued under the fixed designation E1130; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
This is one of a series of test methods for assessing speech privacy in buildings. This specific
standard is designed to assess the speech privacy between locations in open plan spaces, where
occupants are separated only by partial-height partitions and furnishings. Another test method deals
with assessing speech privacy for closed rooms. A related test method deals with the laboratory
measurement of interzone attenuation for open plan components intended to provide speech privacy,
such as partial height space dividers, ceiling systems and wall finishes.
1. Scope expected to reliably predict speech privacy, neither predicts the
specific effective speech privacy afforded to particular indi-
1.1 This test method describes a means of objectively
vidual occupants.
assessing speech privacy between locations in open plan
spaces. This test method relies upon acoustical measurements, 1.5 The values stated in SI units are to be regarded as the
published information on speech levels, and standard methods standard. The inch-pound units in parentheses are for informa-
forassessingspeechcommunication.Thistestmethoddoesnot tion only.
measure the performance of individual open plan components
1.6 This standard does not purport to address all of the
which affect speech privacy; but rather, it assesses the privacy
safety concerns, if any, associated with its use. It is the
whichresultsfromaparticularconfigurationofcomponents (1,
responsibility of the user of this standard to establish appro-
2).
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1.2 This test method is intended to be a field test for the
1.7 This international standard was developed in accor-
assessment of speech privacy in actual open plan spaces.
dance with internationally recognized principles on standard-
However, this test method could be used in mock-up spaces
ization established in the Decision on Principles for the
and in environments arranged to simulate an open plan space.
Development of International Standards, Guides and Recom-
1.3 This test method is suitable for use in many open plan
mendations issued by the World Trade Organization Technical
spaces including traditional open offices, focus areas, and
Barriers to Trade (TBT) Committee.
collaborationspaces.Inadditiontoofficebuildings,thesetypes
of spaces will also be found in healthcare buildings, institu-
2. Referenced Documents
tional spaces, schools, etc. It is not directly applicable for
2.1 ASTM Standards:
measuring the speech privacy between open plan and enclosed
C634 Terminology Relating to Building and Environmental
spaces or between fully enclosed spaces.
Acoustics
1.4 This test method relies upon the Articulation Index,
E1179 Specification for Sound Sources Used for Testing
which objectively predicts the intelligibility of speech. While
Open Office Components and Systems
both the Articulation Index and this test method can be 4
2.2 ANSI Standards:
ANSI/ASA S1.4-2014/PART 1/IEC 61672:1-2013 Specifi-
cation for Sound Level Meters
ThistestmethodisunderthejurisdictionofASTMCommitteeE33onBuilding
and Environmental Acoustics and is the direct responsibility of Subcommittee
E33.02 on Speech Privacy. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2021. Published December 2021. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1986. Last previous edition approved in 2016 as E1130 – 16 DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E1130-16R21. the ASTM website.
2 4
The boldface numbers in parentheses refer to the list of references at the end of Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
this test method. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1130 − 16 (2021)
A,B
TABLE 1 Speech Peaks for Males
ANSI/ASA S1.6-1984 (R2011) Preferred Frequencies, Fre-
One-Third One-Third One-Third
quency Levels, and Band Numbers for Acoustical Mea-
Octave-Band Octave-Band Octave-Band
surements One-Third
Sound Pressure Sound Pressure Sound Pressure
Octave-Band
ANSI/ASA S1.11-2014/Part 1/IEC 61260:1-2014 Specifica-
Levels of Levels of Levels of
Center
Speech Peaks Speech Peaks Speech Peaks
tion for Octave-Band, and Fractional-Octave-Band Ana-
Frequency,
for Casual for Normal for Raised
Hz
log and Digital Filters
Voice Effort Voice Effort Voice Effort
(dB re: 20 µPa) (dB re: 20 µPa) (dB re: 20 µPa)
3. Terminology
200 58 60 63
250 58 64 68
3.1 Definitions:
315 56 63 67
3.1.1 The acoustical terminology used in this test method is
400 59 65 70
500 60 66 72
consistent with Terminology C634. Of special importance are
630 57 64 70
the terms average sound pressure level and arithmetic mean
800 50 58 66
sound pressure level, both of which are defined inTerminology
1000 49 57 65
1250 51 59 66
C634, and source point which is defined in Specification
1600 51 56 63
E1179.
2000 47 52 59
2500 45 53 59
3150 45 53 58
4. Summary of Test Method
4000 47 50 56
4.1 Select two locations in an open plan environment,
5000 46 46 52
A
between which the speech privacy is to be assessed. Designate
Speech peaks calculated from rms values given in (4) by adding 12 dB, in
accordance with (5).
onelocationasthe talkeror sourcelocationandtheotherasthe
B
The A-weighted sound level and linear sound pressure level of the casual voice
listeneror measurementlocation.Theselocationsshouldtypify
effort given in Table 1 are 63 and 67 respectively, for the normal voice effort these
the usual positions of occupants within the open plan space.
are 69 and 73, respectively, and for the raised voice effort are 76 and 78,
respectively.
4.2 All masking sound systems and HVAC systems shall be
operating in their usual manner.
4.3 At the listener location, measure both the ambient sound
reductions given in 4.6 from the chosen reference speech
pressure levels in each one-third octave-band from 200 to 5000
spectrum from Table 1.
Hz and the A-weighted ambient sound level.
4.9 Calculate the signal-to-noise ratio in each one-third
4.4 Locate a qualified sound source (per Specification
octave band by subtracting the measured ambient sound
E1179) at the talker location and orient it toward the listener
pressure levels in 4.3 from the calculated speech levels at the
location. Drive the source with pink (or white) noise at a level
listener location given in 4.8.
sufficient to increase the one-third octave-band sound pressure
levels at the measurement location by at least 10 dB above the
4.10 Calculate the Articulation Index in accordance with
ambient over the entire frequency range of interest. The sound
Section 11 using the one-third octave-band signal-to-noise
pressure levels produced by the sound source at a 1.0 m (3.3 ft)
ratios.
reference position in an anechoic space or free field for a
4.11 Report theArticulation Index to two decimal places as
known electrical input will have been previously established
themeasureofspeechprivacy.Additionally,thespeechprivacy
(3).
index PI may also be reported.
4.5 Measure the sound pressure levels in one-third octave
bands at the listener location with the source operated accord- 5. Significance and Use
ing to 4.4.
5.1 The speech privacy between locations in an open plan
4.6 Calculate the level reduction in each one-third octave space is determined by the degree to which intruding speech
band, that is, the difference in sound pressure levels produced sounds exceed the ambient sound pressure levels at the
by the sound source at the 1.0 m (3.3 ft) reference position per listener’s ear; a classic signal-to-noise ratio situation.
4.4 and that measured at the listener location per 4.5.
5.2 The sound pressure levels at the listener’s ear from
4.7 Select the appropriate reference speech spectra to be intruding speech depend upon:
used for the calculation of the predicted received speech level. 5.2.1 The individual vocal effort and orientation of the
The ‘normal’ voice spectrum of male speech peaks from Table talker,
1 (see also (4) and (5)) must be used in all cases; however, the 5.2.2 The attenuation of speech signals due to distance or
‘casual’ voice spectrum may also be used in cases for focused intervening barriers, and
areaswherebehavioralandtechnicalmeasureshavebeentaken 5.2.3 The reinforcement of speech signals due to reflections
to limit voice levels, and similarly the ‘raised’ voice spectrum from surfaces such as the ceiling, furniture panels, light
may also be used in cases for collaboration areas where group fixtures, walls, or windows.
discussions may occur.
5.3 The ambient sound levels within a space often must be
4.8 Calculate the one-third octave-band sound pressure increased in order to mask intruding speech using an electronic
levelsforthepredictedreceivedspeechspectrumatthelistener sound masking system. However, in certain locations and in
location. This is carried out by subtracting the measured level specific frequency ranges, the building mechanical, electrical
E1130 − 16 (2021)
NOTE 1—If the masking system is adjusted to produce higher sound
and plumbing (MEP) equipment, and the heating, ventilating,
pressure levels, greater speech privacy is obtained; however, the upper
or air conditioning equipment (HVAC) may increase ambient
limit of acceptability is generally determined by the subjective comfort of
sound levels or add tonal noise components that may require
the occupant rather than by speech privacy achieved. In traditional open
mitigation before tuning the masking sound.
plan office spaces, theA-weighted sound level of the background masking
sound is commonly set between 45 and 48 dB. Levels at or above 50 dB
5.4 The primary purpose of this test method is to assess the
should be avoided as these will tend to be annoying in-of-themselves.
speech privacy for an average speech spectrum using the
6.6 The open plan space should be unoccupied during the
standard Articulation Index method. This requires measure-
tests.
ment of the relevant acoustical characteristics discussed in 5.2
and 5.3 for a pair of locations and calculation of the Articula-
NOTE 2—If the purpose of testing is to evaluate the change in speech
tion Index using an average speech spectrum. The average privacy which results from component changes (for example, installing
wall finishes or adjusting the masking system) the different conditions for
speechspectrumisformaletalkersspeakingwithnormalvoice
each test result shall be carefully documented.
effort.Inspecificcasessuchasdesignatedquietworkzonesfor
‘focusedwork’whereadministrativemeasureshavebeentaken
7. Apparatus
to reduce speech levels, a ‘casual’ voice spectrum should be
7.1 The minimum instrumentation required for this test
used to calculate speech privacy, whereas in designated group
method is as follows:
work zones for ‘collaborative work’where lively discussion is
7.1.1 Microphone and Amplifier, that meet or exceed the
expected, a ‘raised’ voice spectrum should be used to calculate
requirements of ANSI S1.4 for Class 1 sound level meters.
speech privacy.
7.1.2 One-Third Octave-Band Filter Set, meeting the re-
5.5 TheArticulation Index ranges from a low value of 0.00,
quirements of ANSI S1.11 for class 1 or better. The nominal
where speech is generally perceived to be unintelligible, to a
center frequencies of the filters shall include all the preferred
high value of 1.00, where all individual spoken words can be
one-third octave bands from 200 to 5000 Hz conforming to
understood. Caution should be exercised in interpreting the
ANSI S1.6. This range may be extended.
numericalAI results of this test method since the percentage of
7.1.3 Sound Level Meter, or other device from which the
single words, phrases, and sentences understood will be
sound pressure level can be read.
different for the same AI value (5).
7.1.4 Calibrated Sound Source, of known sensitivity and
5.6 This test method can be used to:
directivity, completely described in Specification E1179 and
5.6.1 Compare the relative speech privacy afforded between calibrated in accordance with the Annex of this test method.
different locations within open plan spaces.
7.2 On-Site Data Acquisition Instruments, that may consist
5.6.2 Evaluate how changes in open plan components
of a microphone with calibrator, a precision sound level meter
(barriers, furniture, ceilings, masking sound, or wall panels)
capable of measuring average sound pressure level, a one-third
affect speech privacy.
octave-bandanalyzer,andastripchartrecorder(optional).Test
5.6.3 Assess speech privacy objectively for correlation with
data may be read on-site or recorded for later analysis.
subjective responses.
Recording instruments may consist of a microphone with
calibrator, precision sound level meter (optional), and an
5.7 This test method could be one element of a performance
instrument quality recorder. Laboratory data reduction instru-
or acceptance test procedure. However, many additional items
ments may consist of a recorder, a one-third octave-band
would need to be specified to allow the use of this test method
analyzer and a computer.
for performance testing of an open plan environment, such as,
the number of locations to be tested and method of selecting
7.3 The background noise of measuring instruments in each
those locations, and the method of assessing the results.
one-third octave band must be at least 10 dB below the
Specifying a numerical criterion in terms of the Articulation
measured sound pressure levels.
Index is also necessary for acceptance testing; however, the
selection of such a criterion and permissible deviations should
8. Test Signal
be undertaken with care in view of the present state-of-the-art
8.1 The test signal shall be contiguous, one-third octave
as discussed in 5.5.
bands of pink or white noise, from 200 to 5000 Hz, and this
range
...
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