ASTM E3359-23

• Abstract:

  SIGNIFICANCE AND USE; 5.1 ASTM standard test methods that involve sound attenuation and those test methods that involve absorption or decay rates use a noise signal to determine these quantities. The IR method using a sweep signal given in this standard practice can be referenced by these other standards to provide an alternative measurement technique. This alternative technique has the advantage of providing more reliable results in a shorter period of time. ; 5.2 The results obtained with the noise and IR method are considered identical to within the typical measurement uncertainty for the noise method under repeatability conditions. A mandatory validation procedure is given in this practice to ensure a correct implementation of the IR method when developing software or hardware according to the requirements in this standard. ; 5.3 To avoid ambiguity in the implementation of the IR method and to ensure consistent results across different users, this practice prescribes the values of methods and parameters to be used in the signal generation and post-processing. This is in contrast to similar standards describing this method, such as ISO 18233, which provide less guidance.; SCOPE; 1.1 This practice covers the impulse response measurement method using sweep signals, and its use to determine two important room-acoustical quantities: the difference in sound pressure levels between two positions, as used for example in standards determining transmission loss; and decay curves, as used in standards determining the decay rate or reverberation time. ; 1.2 The practice shall be used in conjunction with test methods that use one or both of the quantities described in 1.1. ; 1.3 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. ; 1.4 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. ; 1.5 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.

• Status: Published
• Publication Date: 31-Oct-2023
• Technical Committee: E33 - Building and Environmental Acoustics
• Drafting Committee: E33.05 - Research

Overview

ASTM E3359-23 is a standard practice developed by ASTM International for the measurement of sound pressure level differences and decay curves using the impulse response (IR) method with swept sinusoidal signals. This method is widely used in building and environmental acoustics, particularly for determining transmission loss, decay rates, and reverberation time. Unlike traditional noise-based methods, ASTM E3359-23 prescribes the use of swept sine waves for more reliable, efficient, and reproducible results. It establishes clear procedures for signal generation, measurement, processing, and validation, ensuring the consistency and reliability of sound attenuation and absorption measurements.

Key Topics

• Impulse Response Method: Utilizes swept sinusoidal signals rather than random noise to measure the acoustic properties of a space or material. The IR is extracted from recorded responses and forms the basis for calculating sound pressure levels and decay curves.
• Sound Pressure Level Differences: Specifies the method for determining differences in sound pressure level between two positions, often necessary for evaluating sound transmission loss.
• Decay Curves & Reverberation Time: Provides procedures for measuring the decay of sound pressure after the source is switched off, crucial for quantifying reverberation and absorption characteristics.
• Standardized Parameters: Prescribes essential parameters (e.g., sweep signal type, duration, frequency range, stop margin, truncation length) and methods for signal generation and data post-processing, eliminating ambiguities present in some other international standards.
• Validation Procedure: Requires a mandatory validation step when developing software or hardware implementations, ensuring correct and repeatable measurement results.
• Measurement Uncertainty: Equates the results from this IR method to those from conventional noise methods within typical measurement uncertainties, provided procedures are followed under repeatability conditions.

Applications

ASTM E3359-23 is applicable in a variety of scenarios where precise room acoustical measurement is required:

• Building Acoustics: Evaluating the sound transmission loss of partitions, walls, and floors between adjacent rooms or spaces.
• Room Reverberation Measurement: Determining reverberation time and decay rates in performance halls, auditoria, classrooms, and other built environments where acoustic quality is crucial.
• Product and Material Testing: Assessing the absorption and attenuation properties of materials used in sound insulation and acoustic treatment.
• Acoustic Consulting & Engineering: Supporting consultants and engineers in implementing efficient, repeatable, and reliable sound measurement processes for new builds and renovations.
• Compliance with Acoustic Regulations: Ensuring that measurements for legal, safety, or environmental compliance use recognized and validated methodology.

Related Standards

ASTM E3359-23 references and aligns with several other prominent standards, facilitating integration with industry practices:

• ASTM E2235: Standard method for determination of decay rates for use in sound insulation test methods.
• ASTM E3091: Specification for systems to measure sound levels in various environments.
• ASA/ANSI S1.11 & IEC 61260-1: Specifications for octave-band and fractional-octave-band filters used in acoustic measurements.
• IEC 60268-5: Sound system equipment - specifications for loudspeakers, relevant to the choice of measurement setup.
• ISO 18233: Guidance on new measurement methods in building and room acoustics, although ASTM E3359-23 offers more detailed procedural guidance to ensure consistency.

Practical Value

By standardizing the impulse response method with swept sinusoidal signals, ASTM E3359-23:

• Improves reliability and repeatability of acoustic measurements.
• Reduces measurement time compared to noise-based methods.
• Minimizes ambiguities in test setup and post-processing.
• Facilitates validation and consistent implementation across different software and hardware platforms.

Keywords: sound pressure level difference, decay curve, impulse response, swept sinusoidal signals, reverberation time, sound attenuation, acoustic measurement, ASTM E3359-23.

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: E3359 − 23
Standard Practice for
Measurement of Sound Pressure Level Differences and
Decay Curves Using the Impulse Response Method with
Swept Sinusoidal Signals
This standard is issued under the fixed designation E3359; 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 practice describes the method of using sweep signals to measure impulse responses, and the
subsequent evaluation of decay rates or sound pressure level differences. The signal generation and
post-processing steps are clearly defined to ensure consistent results across different users of the
method. This practice can be referenced in standard methods, in which decay rates or sound pressure
level differences are measured, to replace the conventional random noise method.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This practice covers the impulse response measurement
C634 Terminology Relating to Building and Environmental
method using sweep signals, and its use to determine two
Acoustics
important room-acoustical quantities: the difference in sound
E2235 Test Method for Determination of Decay Rates for
pressure levels between two positions, as used for example in
Use in Sound Insulation Test Methods
standards determining transmission loss; and decay curves, as
E3091 Specification for Systems to Measure Sound Levels
used in standards determining the decay rate or reverberation
2.2 Other Standards:
time.
ASA/ANSI S1.11-2014/Part 1/IEC 61260-1:2014 Electroa-
1.2 The practice shall be used in conjunction with test coustics — Octave-band and fractional-octave-band filters
— Part 1: Specifications
methods that use one or both of the quantities described in 1.1.
IEC 60268-5:2003+A1:2007 Sound system equipment —
1.3 Units—The values stated in SI units are to be regarded 4
Part 5: Loudspeakers
as standard. No other units of measurement are included in this
ISO 18233:2006 Acoustics — Application of new measure-
standard.
ment methods in building and room acoustics
1.4 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
3.1 Terms used in this standard are defined either in Termi-
responsibility of the user of this standard to establish appro-
nology C634 or within this standard. The definition of terms
priate safety, health, and environmental practices and deter-
explicitly given within this standard take precedence over
mine the applicability of regulatory limitations prior to use.
definitions given in Terminology C634. The definitions within
1.5 This international standard was developed in accor-
the terminology section of Terminology C634 and this standard
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Development of International Standards, Guides and Recom-
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
mendations issued by the World Trade Organization Technical
Standards volume information, refer to the standard’s Document Summary page on
Barriers to Trade (TBT) Committee.
the ASTM website.
Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org.
Available from International Electrotechnical Commission (IEC), 3, rue de
This practice is under the jurisdiction of ASTM Committee E33 on Building Varembé, 1st floor, P.O. Box 131, CH-1211, Geneva 20, Switzerland, https://
and Environmental Acoustics and is the direct responsibility of Subcommittee www.iec.ch.
E33.05 on Research. Available from International Organization for Standardization (ISO), ISO
Current edition approved Nov. 1, 2023. Published December 2023. DOI: Central Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,
10.1520/E3359-23. Switzerland, https://www.iso.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E3359 − 23
take precedence over any other definitions found in any other pressure level difference (LD) between two positions or the
documents, including other documents that are referenced in decay curve can be determined through integration over time.
this standard.
5. Significance and Use
3.2 Definitions—The following terms used in this practice
5.1 ASTM standard test methods that involve sound attenu-
have specific meaning that are defined in Terminology C634:
ation and those test methods that involve absorption or decay
background noise, decay rate, reverberation time, sound
rates use a noise signal to determine these quantities. The IR
attenuation, sound pressure level.
method using a sweep signal given in this standard practice can
3.3 Definitions of Terms Specific to This Standard:
be referenced by these other standards to provide an alternative
3.3.1 The following terms are either not in Terminology
measurement technique. This alternative technique has the
C634 or have definitions in this document different from those
advantage of providing more reliable results in a shorter period
stated in the terminology section of Terminology C634.
of time.
3.3.2 backward integration, n—method of obtaining the
5.2 The results obtained with the noise and IR method are
decay curve from an impulse response, achieved by reversing
considered identical to within the typical measurement uncer-
the squared impulse response in time before integration, and
tainty for the noise method under repeatability conditions. A
subsequently reversing the integrated result in time again.
mandatory validation procedure is given in this practice to
3.3.3 decay curve, n—decay of sound pressure level over
ensure a correct implementation of the IR method when
time from steady-state after a sound source has been switched
developing software or hardware according to the requirements
off.
in this standard.
3.3.4 fractional octave band, n—band of frequencies en-
5.3 To avoid ambiguity in the implementation of the IR
compassing an entire octave or fractions of an octave (for
method and to ensure consistent results across different users,
example, one-third of an octave).
this practice prescribes the values of methods and parameters
3.3.5 impulse response, h(t), n—response of a system under
to be used in the signal generation and post-processing. This is
test after excitation with a Dirac delta impulse.
in contrast to similar standards describing this method, such as
3.3.6 intersection time, t [T] (s), n—time instance in seconds
ISO 18233, which provide less guidance.
i
in an impulse response when the idealized straight-line sound
pressure level decay intersects with the constant background 6. Superseding Requirements from Referencing
noise level. Standards
3.3.7 level difference, LD [dimensionless] (dB),
6.1 Unless specified otherwise in the referencing standard,
n—difference in sound pressure level between the sensors at
all of the measurement or instrumentation requirements in this
two different receiver locations.
standard shall be satisfied.
3.3.8 playback device, n—device that uses a sweep signal
7. Sound Source Requirements
stored as digital data to create a voltage signal, which is fed to
the combination of power amplifier and excitation device
7.1 Sound sources shall be loudspeaker systems driven by
(typically a loudspeaker). power amplifiers.
3.3.9 recording device, n—device that receives a voltage
7.2 The combination of sound source and power amplifier
signal from the combination of pre-amplifier and sensor
shall be designed to handle the output levels required for the
(typically a microphone) and converts the voltage signal into
specific measurement to avoid excessively exciting loud-
digital data, which is typically stored before further processing.
speaker non-linearities. The total harmonic distortion (THD) of
the combination of power amplifier and loudspeaker at the
3.3.10 stop margin, [T] (s), n—duration of zero-padding, in
output power level used in the measurements shall not exceed
seconds, added to the end of a sweep signal to continue
10% in the frequency range of interest.
recording the response of the system under test after the
NOTE 1—THD can be measured according to IEC 60268-
excitation has stopped.
5:2003+A1:2007.
-1
3.3.11 sweep rate, [T ] (1/s), n—rate of change of instan-
7.3 If the sound for different frequency bands is radiated
taneous frequency in a sweep signal.
from separate loudspeakers (for example, subwoofer/satellite
3.3.12 sweep signal, n—sinusoidal signal with time-varying
combination), the loudspeakers shall be as close in space to
instantaneous frequency, typically from low to high frequen-
each other as possible.
cies.
8. Restrictions for Sound Sources and Receivers
4. Summary of Practice
8.1 Only stationary sound sources and receivers shall be
4.1 A sinusoidal sweep signal covering the frequency range
used.
of interest is played through a loudspeaker and one or several
8.2 Only a single sound source shall be active at the same
microphones are used to record the response of the system
time in each frequency band.
under test to the sweep signal. The impulse response (IR) of the
NOTE 2—A single sound source in this context can consist of different
system under test is obtained by applying a compensation filter
loudspeakers for different frequency bands that comply with the require-
to the recorded response. From the measured IR, the sound ment in 7.3.
E3359 − 23
9. Averaging of Measurements and Results E3091 specific to the measurement type and environment
described in the referencing standard.
9.1 Longer measurement durations are preferred over aver-
aging multiple shorter measurements (for the same receiver 11.2 The sampling rate of the playback and recording device
position). shall be greater than the center frequency of the highest
fractional octave band of interest by a factor of at least 2.4.
9.2 The measured IR shall not be averaged across source or
receiver positions. 11.3 If the playback and the recording device are not the
same, the sampling rates of both devices shall be set to the
9.3 Averaging of the results for decay rates and level
same value.
differences shall be carried out in accordance with the rules
given in the parent standard. 11.4 If the playback and the recording device are not
synchronized, the recording shall be started before the sweep
10. Sweep Signal
signal playback is started.
10.1 The electrical signal fed to each power amplifier shall
11.5 Play the sweep signal, x(t), and record the response,
be a sinusoidal sweep signal covering the frequency range over
y(t).
which measurements are made.
11.6 If the measurement was carried out according to 11.4,
10.2 The frequency range of the measurements shall be that
x(t) shall be extended in time with zero values to match the
specified in the companion standard for which the measure-
length of y(t) before any further processing.
ments are being made and extended by 10.3.
11.7 For y(t), apply the left half of a Hann window with a
10.3 The frequency range shall be extended by at least one
duration of 4 ms at the beginning of the signal and the right half
half of one-third octave band below and above the frequency
of a Hann window with a duration of 4 ms at the end of the
range of interest.
signal. No window shall be applied to the sweep signal, x(t).
NOTE 3—The windowing process forces the values at the beginning and
10.4 The sweep signal can either be of the linear or
end of the measured signal to zero, which reduces the effect of spectral
exponential type, calculated according to the respective equa-
leakage. Since the sweep signal starts and ends at zero values by design,
tions in A1.1.
no windowing is necessary.
NOTE 4—Because the window duration in 11.7 is very short compared
10.5 The optimal sweep signal parameters depend on the
to the signal length, it is not necessary to adjust the amplitude of the
maximum of the reverberation time (RT) in the frequency
windowed signal to account for the influence of the windowing process.
range of interest, T . The values given below are valid for
max
11.8 Transform the windowed time-domain signal from
spaces with T less than 10 s. For spaces with longer
max
11.7 and the sweep signal, x(t), into the frequency domain
maximum RTs, the signal parameters shall be calculated
using the fast Fourier transform (FFT) to obtain the complex-
according to A1.2.
valued frequency-domain spectra, X~f! and Y~f!. A single FFT
10.5.1 Sound Pressure Level Differences—The sweep dura-
operation over the entire length of the signals shall be used.
tion t to evaluate the sound pressure level shall be at least 10
11.9 Calculate the IR, h(t), by applying the compensation
s for linear and exponential sweeps.
filter, X f , to the measured response in the frequency
10.5.2 Decay Curves—The sweep duration t to evaluate the ~ !
inv,reg
domain, Y f , and then apply the inverse FFT (IFFT):
sound decay shall be at least 20 s for linear and exponential ~ !
sweeps.
h~t! 5 IFFT $Y ~f!·X ~f!% (1)
inv,reg
10.5.3 Decay curves and sound pressure levels can be
11.9.1 The compensation filter, X ~f!, shall be the regu-
evaluated from the same measurement. In that case the longer
inv,reg
larized inverse of the complex spectrum of the sweep signal,
of the two measurement durations shall be chosen.
X~f!, calculated by the method provided in Annex A2.
10.5.4 A longer sweep duration will provide a better signal-
NOTE 5—Values in the frequency domain, such as those obtained by the
to-noise ratio (SNR). Very long measurement durations (>2
FFT algorithm, are complex-valued. This is denoted here by underlined
min) shall be avoided, as they increase the potential of the
characters, for example, Y f .
~ !
measurement being corrupted by time variances and impulsive
NOTE 6—In the rest of this document, it is assumed that the compen-
background noise.
sation filter is applied with circular deconvolution. The procedures and
10.5.5 The sweep signal shall be extended by a zero signal parameters given here are valid for linear deconvolution as well, but the
IR obtained with linear deconvolution must be shifted so that the main
(to extend the total measurement duration) with a duration that
peak in the IR is at 0 s in time.
is equal to or greater than the reverberation time in the highest
one-third octave band of interest, or at least 0.2 s, whichever is
12. Truncation of the Impulse Response
longer. The duration of the signal extension is called the stop
12.1 To reduce the effect of noise and distortion, the IR shall
margin.
be truncated before any further calculation.
10.5.6 The number of samples of the sweep signal, includ-
ing the stop margin according to 10.5.5, shall be an even
12.2 For spaces with T less than 10 s (see section 10.5),
max
number.
the duration l’ of the truncated IR shall be 6 s for the evaluation
of sound pressure level differences, and l’ shall be 12 s for the
11. Measurement Procedure
evaluation of decay curves. For spaces with longer maximum
11.1 The measurement system used to measure and analyze RTs, the duration of the truncated IR shall be calculated
the IR shall conform to the requirements in Specification according to A1.2.
E3359 − 23
t
NOTE 7—The combination of measurement signal length according to i,f
c
D ~t! 5 10 log * h ~τ! 2 N dτ1E (2)
@ #
f 10~ bp,f est,f comp,f !
c c c c
t
10.5 or A1.2 and the truncation length for the IR according to 12.2 ensures
that in most cases the distortion products are removed from the IR before
where h is the truncated, bandpass-filtered IR, E is
bp,f comp,f
further processing. c c
a correction term to compensate for the effect of the IR
13. Bandpass-filtering of the Truncated Impulse
truncation, N is the estimated squared value of the back-
est,f
c
Response ground noise, and t is the intersection time, for each
i,f
c
fractional octave band with center frequency f .
c
13.1 To obtain results in fractional octave bands, apply the
band filters to the truncated IR before further processing. 14.4 The intersection time, background noise estimate, and
value of E shall be determined according to the estima-
comp,f
13.2 Unless otherwise specified in the referencing standard,
c
tion algorithm described in Annex A3.
fractional octave bandpass filters shall fulfill the requirements
of ASA/ANSI S1.11-2014/Part 1/IEC 61260-1:2014.
...