ASTM E1573-22

Standard Test Method for Measurement and Reporting of Masking Sound Levels Using A-Weighted and One-Third-Octave-Band Sound Pressure Levels

SIGNIFICANCE AND USE
5.1 Acoustical performance is dependent on many factors (see Guide E1374 for a discussion on general office acoustical considerations). One of these factors is the masking sound. The masking spectrum shape and level must conform within specified tolerances throughout the treated area. The measurement and recording of these parameters are addressed in this test method.  
5.2 The results from this test method are used to determine if the masking sound meets a particular specification.
SCOPE
1.1 This test method specifies the procedure used to measure the masking sound in terms of A-weighted and one-third-octave-band sound pressure levels.  
1.2 The results of this test method can be used to determine if and where the masking sound meets (or does not meet) a particular specification.  
1.3 This test method does not evaluate the overall acoustical environment. It is intended only to measure and report the masking sound levels.  
1.4 The values stated in SI units are to be regarded as standard. The values in parentheses are for information only.  
1.5 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.  
1.6 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.

General Information

• Status: Published
• Publication Date: 31-May-2022
• ICS: 91.120.20 - Acoustics in building. Sound insulation
• Technical Committee: E33 - Building and Environmental Acoustics
• Drafting Committee: E33.02 - Speech Privacy

Relations

• Refers: ASTM E1374-18 - Standard Guide for Open Office Acoustics and Applicable ASTM Standards
• Effective Date: 01-Jan-2018
• Refers: ASTM E1374-18e1 - Standard Guide for Office Acoustics and Applicable ASTM Standards
• Effective Date: 01-Jan-2018
• Refers: ASTM C634-13 - Standard Terminology Relating to Building and Environmental Acoustics
• Effective Date: 01-Sep-2013
• Refers: ASTM C634-11 - Standard Terminology Relating to Building and Environmental Acoustics
• Effective Date: 01-Dec-2011
• Refers: ASTM E1374-06(2011) - Standard Guide for Open Office Acoustics and Applicable ASTM Standards
• Effective Date: 01-Nov-2011
• Refers: ASTM C634-10a - Standard Terminology Relating to Building and Environmental Acoustics
• Effective Date: 01-Sep-2010
• Refers: ASTM C634-10 - Standard Terminology Relating to Building and Environmental Acoustics
• Effective Date: 01-Jun-2010
• Refers: ASTM C634-09 - Standard Terminology Relating to Building and Environmental Acoustics
• Effective Date: 01-Apr-2009
• Refers: ASTM C634-08a - Standard Terminology Relating to Building and Environmental Acoustics
• Effective Date: 01-Sep-2008
• Refers: ASTM C634-08 - Standard Terminology Relating to Building and Environmental Acoustics
• Effective Date: 15-Mar-2008
• Refers: ASTM E1374-06 - Standard Guide for Open Office Acoustics and Applicable ASTM Standards
• Effective Date: 01-Apr-2006
• Refers: ASTM E1374-93(1998)e1 - Standard Guide for Open Office Acoustics and Applicable ASTM Standards
• Effective Date: 10-Apr-2002
• Refers: ASTM C634-02e1 - Standard Terminology Relating to Building and Environmental Acoustics
• Effective Date: 10-Apr-2002
• Refers: ASTM C634-02 - Standard Terminology Relating to Environmental Acoustics
• Effective Date: 10-Apr-2002
• Refers: ASTM E1374-02 - Standard Guide for Open Office Acoustics and Applicable ASTM Standards
• Effective Date: 10-Apr-2002

Overview

ASTM E1573-22: Standard Test Method for Measurement and Reporting of Masking Sound Levels Using A-Weighted and One-Third-Octave-Band Sound Pressure Levels specifies procedures for accurately measuring and reporting masking sound in various environments. This standard focuses on ensuring that the shape and level of masking sound spectra meet required specifications, supporting optimal speech privacy and acoustic performance-especially in office and workplace settings.

Adhering to ASTM E1573-22 helps facility managers, acoustical consultants, and building owners verify if installed sound masking systems conform to specified design criteria. The results are essential for maintaining consistent sound levels, minimizing distractions, and supporting productive, private work environments.

Key Topics

• Masking Sound Measurement: Provides procedures to measure masking sound with both A-weighted and one-third-octave-band sound pressure levels.
• Representative Sampling: Advises on correct measurement locations and quantities for both open-plan and enclosed office spaces, ensuring comprehensive coverage.
• Microphone Positioning: Outlines guidelines for microphone height, distance from reflective surfaces, and sweep methodology to achieve reliable readings.
• Test Signal Options: Allows measurement of:
  • Combined sound masking and HVAC system noise
  • Sound masking system alone
  • HVAC system alone
• Instrumentation Requirements: Calls for measurement devices compliant with international standards (IEC 61672-1 and IEC 61260-1).
• Reporting Requirements: Details the necessary information for reporting, including instrument details, measurement locations, test conditions, and comparison of measured results with specifications.
• Precision and Bias: Notes reproducibility parameters within controlled office environments and emphasizes unbiased, method-defined measurement values.

Applications

Implementing ASTM E1573-22 delivers practical value in a range of settings where sound masking is critical:

• Open and Closed Offices: Confirms the even distribution and compliance of masking sound levels, supporting productivity and speech privacy.
• New Office Fit-Outs: Ensures that installed sound masking or HVAC systems meet acoustic criteria before occupancy.
• Occupant Complaint Investigations: Provides a standardized method for assessing claims regarding noisy or insufficiently masked environments.
• Sound Masking Commissioning: Validates system performance during installation or after reconfiguration of office layouts and furnishings.

Key benefits include:

• Improved speech privacy and reduced distraction in open plan and private offices
• Reliable data to inform acoustic adjustments or system recalibration
• Standardized reporting for compliance and documentation

Related Standards

ASTM E1573-22 aligns with and references several important standards:

• ASTM E1374: Guide for Office Acoustics and Applicable ASTM Standards-offering broader guidance on office acoustical environments.
• ASTM C634: Terminology Relating to Building and Environmental Acoustics-providing consistency in acoustical language and definitions.
• IEC 61672-1: Electroacoustics - Sound level meters-specifying the performance requirements for sound level measurement equipment.
• IEC 61260-1: Electroacoustics - Octave-band and fractional-octave-band filters-ensuring the accuracy of equipment used for frequency band measurements.

Staying up to date with these standards ensures compatibility, regulatory compliance, and accurate measurement and reporting practices within the field of building acoustics.

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Keywords: ASTM E1573-22, masking sound level measurement, A-weighted sound, one-third-octave-band sound pressure, sound masking system, office acoustics, speech privacy, acoustical testing, open offices, building standards.

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: E1573 − 22
Standard Test Method for
Measurement and Reporting of Masking Sound Levels
Using A-Weighted and One-Third-Octave-Band Sound
Pressure Levels
This standard is issued under the fixed designation E1573; 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 test method is one of a set of standards relating to the acoustical performance of components
orsystemsinopenandclosedofficesettings.Theotherstandardsinthissetdealwiththemeasurement
of the sound attenuation between work stations provided by partial height space dividers, vertical
surfaces, acoustical ceiling systems; and speech privacy in open and closed spaces.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This test method specifies the procedure used to mea-
C634 Terminology Relating to Building and Environmental
sure the masking sound in terms ofA-weighted and one-third-
Acoustics
octave-band sound pressure levels.
E1374 Guide for Office Acoustics and Applicable ASTM
1.2 The results of this test method can be used to determine
Standards
if and where the masking sound meets (or does not meet) a
2.2 IEC Standards:
particular specification.
IEC 61260:1 Electroacoustics - Octave-band and fractional-
1.3 This test method does not evaluate the overall acoustical
octave-band filters - Part 1: Specifications
environment. It is intended only to measure and report the
IEC 61672:1 Electroacoustics - Sound Level meters - Part 1:
masking sound levels.
Specifications
1.4 The values stated in SI units are to be regarded as
NOTE 1—The IEC standards are often adopted by national standards
organizations as national standards sometimes with additional unique
standard. The values in parentheses are for information only.
national standards numbers assigned.
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3. Terminology
responsibility of the user of this standard to establish appro-
3.1 Terms used in this standard are defined either in Termi-
priate safety, health, and environmental practices and deter-
nology C634 or within this standard. The definitions of terms
mine the applicability of regulatory limitations prior to use.
explicitly given within this standard take precedence over
1.6 This international standard was developed in accor-
definitions given in Terminology C634. The definitions within
dance with internationally recognized principles on standard-
Terminology C634 and this standard take precedence over any
ization established in the Decision on Principles for the
other definitions of defined terms found in any other
Development of International Standards, Guides and Recom-
documents, including other documents referenced in this stan-
mendations issued by the World Trade Organization Technical
dard.
Barriers to Trade (TBT) Committee.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
ThistestmethodisunderthejurisdictionofASTMCommitteeE33onBuilding contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
and Environmental Acoustics and is the direct responsibility of Subcommittee Standards volume information, refer to the standard’s Document Summary page on
E33.02 on Speech Privacy. the ASTM website.
CurrenteditionapprovedJune1,2022.PublishedJuly2022.Originallyapproved Available from International Electrotechnical Commission (IEC), 3, rue de
in 1993. Last previous edition approved in 2018 as E1573 – 18. DOI: 10.1520/ Varembé, 1st Floor, P.O. Box 131, CH-1211, Geneva 20, Switzerland, http://
E1573-22. www.iec.ch.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1573 − 22
3.2 Definitions of Terms Specific to This Standard: 7.4 If the intent is to measure the sound generated only by
3.2.1 masking sound, n—sound that reduces the intelligibil- the HVAC system and other building sources, the HVAC
ity of speech and the distraction of activity noise. system and other sound sources shall be operated at their
3.2.1.1 Discussion—Masking sound is produced and con- normal daytime conditions.
trolled most effectively by an electronic sound masking sys-
7.5 Sound masking features such as adaptive level adjust-
tem.
ment or programmable timer shall be deactivated and set to the
3.2.2 sound masking system, n—electronic equipment and
specified base levels during measurements.
loudspeakers used to generate, distribute, and control masking
NOTE 2—Testing the HVAC system alone will typically occur in order
sound throughout a treated area.
to verify the need for electronic sound masking and conversely, to
determine the areas within a facility where the HVAC levels may already
4. Summary of Test Method
exceed ideal masking sound levels.
NOTE 3—When the masking system is measured without the HVAC as
4.1 The conformity of the masking sound to a specified
per 7.1.2, the subsequent restoration of the HVAC may result in combined
curve and level is determined by measuring the A-weighted
ambient noise levels that are unacceptable to the occupants.
sound level and the one-third-octave-band sound pressure
levels at sufficiently representative locations with a sound level
8. Test Instrumentation and Microphone Positioning
meter and comparing these values to specified levels.
8.1 Instrumentation Specification:
5. Significance and Use
8.1.1 The sound level meter or analyzer shall be an
integrating-averaging type with appropriate microphone that
5.1 Acoustical performance is dependent on many factors
conforms to class 1, IEC 61672:1-2013 requirements.
(see Guide E1374 for a discussion on general office acoustical
8.1.2 The measurement system shall include one-third-
considerations). One of these factors is the masking sound.The
masking spectrum shape and level must conform within octave-band filters that conform to IEC 61260:1-2014 for class
1.
specified tolerances throughout the treated area. The measure-
ment and recording of these parameters are addressed in this 8.1.3 Test data may be acquired on-site or recorded for later
analysis. The combined frequency response and other charac-
test method.
teristics of the measurement system and recording device shall
5.2 The results from this test method are used to determine
meet the class 1 requirements of IEC 61672:1-2013.
if the masking sound meets a particular specification.
8.2 Microphone Orientation and Positioning:
6. Test Space
8.2.1 The measurement system will typically include a 12.7
6.1 The test space shall include the entire area of the
mm ( ⁄2 in.) microphone which will have either a free-field or
building served by the masking system. random incidence inherent directivity response and the system
may include electronic circuitry allowing the microphone to
6.2 The ceiling system of the test space shall be completely
simulateeitherdirectivityresponse.Resultsabovearound5000
finished, including light fixtures and air diffusers.
Hz can be influenced by the microphone directivity response,
6.3 The floor covering and all wall finishes shall be com-
the degree of diffusivity of the sound field, and the orientation
pletely installed prior to testing.
of the microphone if the field is not highly diffuse. These
6.4 All interior furnishings shall be in place. concerns can be avoided by use of a 6.4 mm ( ⁄4 in.)
microphone. For indoor measurements, it is often assumed that
6.5 The test space shall be unoccupied during the tests.
the field is diffusive, and a random incidence response micro-
7. Test Signal phone or setting is preferred with the orientation insignificant.
Use of a free-field microphone in such fields will result in
7.1 The test signal used for this evaluation may be any of
slightly low readings at higher frequencies. Large open plan
the following:
spacesmaynotbediffuse.Especiallyifitiscleartotheearthat
7.1.1 The sound due to the HVAC system and the sound
the dominant sound is from above, it is preferable in such
masking system combined, or
spaces to use either a free-field response with the microphone
7.1.2 The sound due to the sound masking system alone, or
pointed upward, or a random-incidence response with the
7.1.3 The sound due to the HVAC system alone.
microphone pointed at about 45° above the horizontal. The
7.2 For the case described in 7.1.1, the test procedures shall
microphone directivity response and orientation shall be pro-
be conducted with the sound masking system and all other
vided in the report.
background sound sources operational. The HVAC system
8.2.2 The center of the microphone sweep position(s) shall
shall be operated at its normal daytime condition.
be at ear-height for the average seated person which is 1.2 m (4
7.3 For the case described in 7.1.2, the test procedures shall ft) above the floor.
be conducted with the sound masking system only. Noise 8.2.3 The microphone sweep position(s) shall be selected if
generated by other background
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E1573 − 18 E1573 − 22
Standard Test Method for
Measurement and Reporting of Masking Sound Levels
Using A-Weighted and One-Third-Octave-Band Sound
Pressure Levels
This standard is issued under the fixed designation E1573; 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 test method is one of a set of standards relating to the acoustical performance of components
or systems in open and closed office settings. The other standards in this set deal with the measurement
of the sound attenuation between work stations provided by partial height space dividers, vertical
surfaces, acoustical ceiling systems; and speech privacy in open and closed spaces.
1. Scope
1.1 This test method specifies the procedure used to measure the masking sound in terms of A-weighted and one-third-octave-band
sound pressure levels.
1.2 The results of this test method can be used to determine if and where the masking sound meets (or does not meet) a particular
specification.
1.3 This test method does not evaluate the overall acoustical environment. It is intended only to measure and report the masking
sound levels.
1.4 The values stated in SI units are to be regarded as standard. The values in parentheses are for information only.
1.5 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.
1.6 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.
2. Referenced Documents
2.1 ASTM Standards:
This test method is under the jurisdiction of ASTM Committee E33 on Building and Environmental Acoustics and is the direct responsibility of Subcommittee E33.02
on Speech Privacy.
Current edition approved Jan. 1, 2018June 1, 2022. Published February 2018July 2022. Originally approved in 1993. Last previous edition approved in 20092018 as
E1573 – 09.E1573 – 18. DOI: 10.1520/E1573-18.10.1520/E1573-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1573 − 22
C634 Terminology Relating to Building and Environmental Acoustics
E1374 Guide for Office Acoustics and Applicable ASTM Standards
2.2 IEC Standards:
IEC 61260:1 Electroacoustics - Octave-band and fractional-octave-band filters - Part 1: Specifications
IEC 61672:1 Electroacoustics - Sound Level meters - Part 1: Specifications
NOTE 1—The IEC standards are often adopted by national standards organizations as national standards sometimes with additional unique national
standards numbers assigned.
3. Terminology
3.1 Definitions:
3.1.1 The acoustical terminology used in this test method is consistent with the definitions in Terminology C634.
3.1 Terms used in this standard are defined either in Terminology C634 or within this standard. The definitions of terms explicitly
given within this standard take precedence over definitions given in Terminology C634. The definitions within Terminology C634
and this standard take precedence over any other definitions of defined terms found in any other documents, including other
documents referenced in this standard.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 masking sound—sound, n—sound that reduces the intelligibility of speech and the distraction of activity noise.
3.2.1.1 Discussion—
Masking sound is produced and controlled most effectively by an electronic sound masking system.
3.2.2 sound masking system—system, n—electronic equipment and loudspeakers used to generate, distribute, and control masking
sound throughout a treated area.
4. Summary of Test Method
4.1 The conformity of the masking sound to a specified curve and level is determined by measuring the A-weighted sound level
and the one-third-octave-band sound pressure levels at sufficiently representative locations with a sound level meter and comparing
these values to specified levels.
5. Significance and Use
5.1 Acoustical performance is dependent on many factors (see Guide E1374 for a discussion on general office acoustical
considerations). One of these factors is the masking sound. The masking spectrum shape and level must conform within specified
tolerances throughout the treated area. The measurement and recording of these parameters are addressed in this test method.
5.2 The results from this test method are used to determine if the masking sound meets a particular specification.
6. Test Space
6.1 The test space shall include the entire area of the building served by the masking system.
6.2 The ceiling system of the test space shall be completely finished, including light fixtures and air diffusers.
6.3 The floor covering and all wall finishes shall be completely installed prior to testing.
6.4 All interior furnishings shall be in place.
6.5 The test space shall be unoccupied during the tests.
Available from International Electrotechnical Commission (IEC), 3, rue de Varembé, 1st Floor, P.O. Box 131, CH-1211, Geneva 20, Switzerland, http://www.iec.ch.
E1573 − 22
7. Test Signal
7.1 The test signal used for this evaluation may be any of the following:
7.1.1 The sound due to the HVAC system and the sound masking system combined, or
7.1.2 The sound due to the sound masking system alone, or
7.1.3 The sound due to the HVAC system alone.
7.2 For the case described in 7.1.1, the test procedures shall be conducted with the sound masking system and all other background
sound sources operational. The HVAC system shall be operated at its normal daytime condition.
7.3 For the case described in 7.1.2, the test procedures shall be conducted with the sound masking system only. Noise generated
by other background sound sources shall be at least 10 dB below the masking signal in all respective one-third-octave-bands. The
HVAC system shall be shut off and any remaining sounds that may interfere with the measurements shall be noted in the report.
7.4 If the intent is to measure the sound generated only by the HVAC system and other building sources, the HVAC system and
other sound sources shall be operated at their normal daytime conditions.
7.5 Sound masking features such as adaptive level adjustment or programmable timer shall be deactivated and set to the specified
base levels during measurements.
NOTE 2—Testing the HVAC system alone will typically occur in order to verify the need for electronic sound masking and conversely, to determine the
areas within a facility where the HVAC levels may already exceed ideal masking sound levels.
NOTE 3—When the masking system is measured without the HVAC as per 7.1.2, the subsequent restoration of the HVAC may result in combined ambient
noise levels that are unacceptable to the occupants.
8. Test Instrumentation and Microphone Positioning
8.1 Instrumentation Specification:
8.1.1 The sound level meter or analyzer shall be an integrating-averaging type with appropriate microphone that conforms to class
1, IEC 61672:1-2013 requirements.
8.1.2 The measurement system shall include one-third-octave-band filters that conform to IEC 61260:1-2014 for class 1.
8.1.3 Test data may be acquired on-site or recorded for later analysis. The combined frequency response and other characteristics
of the measurement system and recording device shall meet the class 1 requirements of IEC 61672:1-2013.
8.2 Microphone Orientation and Positioning:
8.2.1 The measurement system will typically include a 12.7 mm ( ⁄2 in.) microphone which will have either a free-field or random
incidence inherent directivity response and the system may include electronic circuitry allowing the microphone to simulate either
directivity response. Results above around 5000 Hz can be influenced by the microphone directivity response, the degree of
diffusivity of the sound field, and the orientation of the microphone if the field is not highly diffuse. These concerns can be avoided
by use of a 6.4 mm ( ⁄4 in.) microphone. For indoor measurements, it is often assumed that the field is diffusive, and a random
incidence response microphone or setting is preferred with the orientation insignificant. Use of a free-field microphone in such
fields will result in slightly low readings at higher frequencies. Large open plan spaces may not be diffuse. Especially if it is clear
to the ear that the dominant sound is from above, it is preferable in such spaces to use either a free-field response with the
microphone poin
...