ASTM E1130-90(1994)e1

Standard Test Method for Objective Measurement of Speech Privacy in Open Offices Using Articulation Index

SCOPE
1.1 This test method describes a means of measuring speech privacy objectively between locations in open offices. 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 office components which affect speech privacy; it measures the privacy which results from a particular configuration of components (1, 2).
1.2 This test method is intended to be a field test for the measurement of speech privacy in actual open offices. However, this test method could be used in an environment arranged to simulate an open office.
1.3 This test method could be adapted for use in other open plan spaces such as open plan schools. It could also be adapted 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 predicts the intelligibility of speech for a group of talkers and listeners. While both the Articulation Index and this test method can be expected to reliably predict average speech privacy, neither predicts the specific degree of speech privacy afforded to particular open office 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Jan-2002
• ICS: 17.140.01 - Acoustic measurements and noise abatement in general
• Technical Committee: E33 - Building and Environmental Acoustics
• Drafting Committee: E33.02 - Speech Privacy

Relations

• Replaced By: ASTM E1130-02 - Standard Test Method for Objective Measurement of Speech Privacy in Open Offices Using Articulation Index
• Effective Date: 10-Jan-2002
• Referred By: ASTM E2638-10(2017) - Standard Test Method for Objective Measurement of the Speech Privacy Provided by a Closed Room
• Effective Date: 10-Jan-2002
• Referred By: ASTM C634-22 - Standard Terminology Relating to Building and Environmental Acoustics
• Effective Date: 10-Jan-2002
• Referred By: ASTM E1374-18e1 - Standard Guide for Office Acoustics and Applicable ASTM Standards
• Effective Date: 10-Jan-2002
• Referred By: ASTM E3091-17 - Standard Specification for Systems to Measure Sound Levels
• Effective Date: 10-Jan-2002
• Referred By: ASTM E1179-13(2019) - Standard Specification for Sound Sources Used for Testing Open Office Components and Systems
• Effective Date: 10-Jan-2002

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
e1
Designation: E 1130 – 90 (Reapproved 1994)
Standard Test Method for
Objective Measurement of Speech Privacy in Open Offices
Using Articulation Index
This standard is issued under the fixed designation E 1130; 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 (e) indicates an editorial change since the last revision or reapproval.
e NOTE—Keywords were added editorially in December 1994.
INTRODUCTION
This is one of a series of test methods for evaluating the acoustical characteristics of open office
environments and the performance of acoustical components. Other proposed test methods in this
series deal with the laboratory measurement of interzone attenuation of partial height space dividers
and ceiling systems.
1. Scope responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
1.1 This test method describes a means of measuring speech
bility of regulatory limitations prior to use.
privacy objectively between locations in open offices. This test
method relies upon acoustical measurements, published infor-
2. Referenced Documents
mation on speech levels, and standard methods for assessing
2.1 ASTM Standards:
speech communication. This test method does not measure the
C 384 Test Method for Impedance and Absorption of
performance of individual open office components which affect
Acoustical Materials by the Impedance Tube Method
speech privacy; it measures the privacy which results from a
C 634 Terminology Relating to Environmental Acoustics
particular configuration of components (1, 2).
E 1041 Guide for Measurement of Masking Sound in Open
1.2 This test method is intended to be a field test for the
Offices
measurement of speech privacy in actual open offices. How-
E 1179 Specification for Sound Sources Used for Testing
ever, this test method could be used in an environment
Open Office Components and Systems
arranged to simulate an open office.
2.2 ANSI Standards:
1.3 This test method could be adapted for use in other open
S1.4 Specification for Sound Level Meters
plan spaces such as open plan schools. It could also be adapted
S1.6 Preferred Frequencies and Band Numbers for Acous-
for measuring the speech privacy between open plan and
tical Measurements
enclosed spaces or between fully enclosed spaces.
S1.11 Specification for Octave, Half-Octave and One-Third
1.4 This test method relies upon the Articulation Index
Octave Band Filter Sets
which predicts the intelligibility of speech for a group of
S3.5 Methods for the Calculation of the Articulation Index
talkers and listeners. While both the Articulation Index and this
test method can be expected to reliably predict average speech
3. Terminology
privacy, neither predicts the specific degree of speech privacy
3.1 Definitions—The acoustical terminology used in this
afforded to particular open office occupants.
test method is consistent with Terminology C 634. Of special
1.5 The values stated in SI units are to be regarded as the
importance are the terms average sound pressure level and
standard. The inch-pound units in parentheses are for informa-
arithmetic mean sound pressure level, both of which are
tion only.
defined in Terminology C 634, and source point which is
1.6 This standard does not purport to address all of the
defined in Specification E 1179.
safety concerns, if any, associated with its use. It is the
4. Summary of Test Method
4.1 Select two locations in an open office environment,
This test method is under the jurisdiction of ASTM Committee E-33 on
between which the speech privacy is to be measured. Designate
Environmental Acoustics and is the direct responsibility of Subcommittee E33.02 on
Open Plan Spaces.
Current edition approved Mar. 30, 1990. Published May 1990. Originally
published as E 1130 – 86. Last previous edition E 1130 – 88. Annual Book of ASTM Standards, Vol 04.06.
2 4
The boldface numbers in parentheses refer to the list of references at the end of Available from American National Standards Institute, 11 W. 42nd St., 13th
this test method. Floor, New York, NY 10036.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
E 1130
one location as the talker or source location and the other as the ANSI S3.5 using the one-third octave-band signal-to-noise
listener or measurement location. These locations should typify ratios.
the usual working positions of office occupants. 4.11 Report the Articulation Index to two decimal places as
4.2 All masking sound systems and HVAC systems shall be the measure of speech privacy.
operating in their usual manner.
5. Significance and Use
4.3 At the listener location, measure the ambient sound
5.1 The speech privacy between open offices is determined
pressure levels in each one-third octave-band from 200 to 5000
by the degree to which intruding speech sounds from adjacent
Hz and the A-weighted sound level.
offices exceed the ambient sound pressure levels at the listen-
4.4 Locate a qualified sound source at the talker location
er’s ear; a classic signal-to-noise ratio situation.
and orient it toward the listener location. Drive the source with
5.2 The sound pressure levels at the listener’s ear from
pink or white noise at a level sufficient to increase the one-third
speech in adjacent offices depend upon:
octave-band sound pressure levels at the measurement location
5.2.1 The individual vocal effort and orientation of the
by at least 10 dB above the ambient over the entire frequency
talker,
range of interest. The sound pressure levels produced by the
5.2.2 The attenuation of speech signals due to distance or
sound source at a 0.9-m (3-ft) reference position for a known
intervening barriers, and
electrical input will have been previously established (3).
5.2.3 The reinforcement of speech signals due to reflections
4.5 Measure the sound pressure levels in one-third octave
from office surfaces such as the ceiling, furniture panels, light
bands at the listener location with the source on.
fixtures, walls, or windows.
4.6 Calculate the level reduction in each one-third octave
5.3 The ambient sound pressure levels will usually be
band, that is, the difference in sound pressure levels produced
controlled to mask intruding speech. This is accomplished by
by the sound source at 0.9 m (3 ft) and at the listener location.
means of a masking sound system. However, in certain
4.7 Determine the speech spectra to be used. The normal
positions and frequency ranges, heating, ventilating, or air
voice spectrum of male speech peaks from Table 1 must be
conditioning equipment (HVAC) may contribute significantly
used; optionally, additional spectra may be used.
to ambient sound pressure levels. Guide E 1041 may be used to
4.8 Calculate the one-third octave-band sound pressure
measure masking sound.
levels for the speech spectrum at the listener location. This is
5.4 The primary purpose of this test method is to measure
carried out by subtracting the measured level reductions from
the speech privacy for an average speech spectrum using the
the speech spectrum.
standard Articulation Index method. This requires measure-
4.9 Calculate the signal-to-noise ratio in each one-third
ment of the relevant acoustical characteristics discussed in 5.2
octave band by subtracting the measured ambient and sound
and 5.3 for a pair of offices and calculation of the Articulation
pressure levels from the calculated speech levels at the listener
Index using an average speech spectrum. The average speech
location.
spectrum is for male talkers speaking with normal voice effort.
4.10 Calculate the Articulation Index in accordance with
5.5 The Articulation Index ranges from 0.00, where speech
A,B
TABLE 1 Speech Peaks for Males
is unintelligible, to 1.00, where all individual spoken words can
One-Third One-Third
be understood. Caution should be exercised in interpreting the
Octave-Band Octave-Band
numerical results of this test method. There is a need for further
One-Third
Sound Pressure Sound Pressure
Octave-Band
research to establish the relationship of Articulation Index to
Levels of Levels of
Center
Speech Peaks Speech Peaks
speech privacy. One purpose of this test method is to encourage
Frequency,
for Normal for Raised
Hz the measurement of data and further research on this topic
Voice Effort Voice Effort
perhaps leading to development of well-documented speech
(dB re: 20 μPa) (dB re: 20 μPa)
privacy categories and criteria. The user is cautioned not to rely
200 60 63
250 64 68 upon Fig. 15 of ANSI S3.5 to interpret the numerical results
315 63 67
because the ANSI standard is primarily communication-
400 65 70
oriented rather than privacy-oriented. The Appendix presents
500 66 72
630 64 70 useful interim guidelines pending further research.
800 58 66
5.6 This test method can be used to:
1000 58 65
5.6.1 Compare the relative privacy afforded between differ-
1250 59 67
1600 56 63 ent pairs of open offices.
2000 52 59
5.6.2 Evaluate how changes in open office components
2500 53 60
(barriers, furniture, ceilings, masking sound, or wall panels)
3150 53 58
4000 50 56 affect speech privacy.
5000 46 52
5.6.3 Measure speech privacy objectively for correlation
A
Speech peaks calculated from rms values given in Ref (4) by adding 12 db, in
with subjective responses.
accordance with ANSI S3.5. Values given in Ref (4) are normalized to 1 m and are
5.7 This test method could be one element of a performance
used in this test method as representative values for 0.9 m.
B
or acceptance test procedure. However, many additional items
The A-weighted sound level and linear sound pressure level of the normal voice
effect spectrum given in Table 1 are 70 dBA and 73 dB, respectively. The
would need to be specified to use this test method for
corresponding levels for the raised voice effort spectrum are 76 dBA and 78 dB.
performance testing of an open office environment, such as, the
These may be compared to the levels for the “idealized speech peak spectrum”
given in Table 8 of ANSI S3.5, 74 dBA and 77 dB. number of office pairs to be tested and method of selecting
E 1130
those offices, and the method of averaging the results. Speci- of a microphone with calibrator, a precision sound level meter
fying a numerical criterion in terms of the Articulation Index is capable of measuring average sound pressure level, a one-third
also necessary for acceptance testing; however, the selection of octave-band analyzer, and a strip chart recorder (optional). Test
such a criterion and permissible deviations should be under- data may be read on-site or tape recorded for later analysis.
taken with care in view of the present state-of-the-art as Recording instruments may consist of a microphone with
discussed in 5.5. calibrator, precision sound level meter (optional), and an
5.8 Recent data on speech levels as discussed in Ref (4) are instrument quality tape recorder. Laboratory data reduction
normalized to 1 m (3.3 ft). However, recently developed test instruments may consist of a tape recorder, a one-third octave-
methods for evaluating open office components and systems, band analyzer and a computer.
including this test method, have been developed using dis- 7.3 The background noise of measuring instruments in each
tances standardized in U.S. customary units (feet). This test one-third octave band must be at least 10 dB below measured
method assumes that speech levels at 0.9 m (3 ft) and1mare sound pressure levels.
equivalent. This is a reasonable and conservative assumption
8. Test Signal
considering that the standard deviation of normal voice speech
8.1 The test signal shall be contiguous, one-third octave
levels is several decibels or more as discussed in Ref (4). Using
a point source model of spherical spreading, the difference in bands of pink or white noise, from 200 to 5000 Hz, and may be
extended.
sound pressure levels between 0.9 and1m(3and3.3ft) would
be at most 1 dB.
9. Speech Spectra
6. Test Space
9.1 The normal voice effort spectrum (2) of speech peaks
6.1 The test space shall be an actual or a mock-up open
given in Table 1 shall be used for the calculations. Additionally,
office environment.
other spectra may be used such as the raised voice spectrum of
6.2 The ceiling of the test space shall be complete, including
speech peaks in Table 1.
ceiling board, light fixtures, and air diffusers.
6.3 The floor covering and wall finishes shall be completely 10. Procedure
installed prior to testing.
10.1 Measurement Location:
6.4 Office furnishings shall be in place.
10.1.1 Select a listener (measurement) location at the typi-
6.5 Any masking sound system shall be set as intended for
cal ear-height of a seated listener, that is, the microphone shall
use in the occupied space.
be located 1.2 m (4 ft) above the floor.
10.1.2 The measurement location should be at least 1 m (3.3
NOTE 1—If the masking system is adjusted to produce significantly
higher sound pressure levels, greater speech privacy is obtained; however, ft) from any vertical surfaces such as walls, columns, desks, or
the higher levels may be found unacceptably annoying.
office furniture. In the event that this cannot be met, the
selected location shall be at the usual worker’s position.
6.6 The open office space should be unoccupied during the
10.2 Ambient Measurements:
tests.
10.2.1 With the test signal off, the average sound pressure
NOTE 2—If the purpose of testing is to evaluate the change in speech
level shall be measured in each one-third octave band over a
privacy which results from component changes (for example, installing
time period of at least4sat four positions at 90° intervals
wall finishes or adjusting the masking system) the different conditions for
around a circle of 0.3-m (1-ft) radius centered on the location.
each test result shall be carefully documented.
The arithmetic mean sound pressure level shall be calculated
7. Apparatus
for each band from the four measured values. The A-weighted
7.1 The minimum instrumentation required for this test sound level shall also be measured and calculated in this
method is as follows: manner. All data shall be obtained with the microphone
7.1.1 Microphone and Amplifier, that meet or exceed the diaphragm parallel to the floor and facing upwards.
requirements of ANSI S1.4 for Type 1 sound level meters. A 10.2.2 Verify that the measured ambient sound pressure
random incidence microphone shall be used, that is, one that levels exceed the background noise of the instruments by at
has its flattest frequency response
...