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SIST EN ISO 3382-1:2009
01-september-2009
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SIST EN ISO 3382:2001
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Acoustics - Measurement of room acoustic parameters - Part 1: Performance spaces
(ISO 3382-1:2009)
Acoustique - Mesurage des parametres acoustiques des salles - Partie 1: Salles de
spectacles (ISO 3382-1:2009)
Ta slovenski standard je istoveten z: EN ISO 3382-1:2009
ICS:
17.140.01 $NXVWLþQDPHUMHQMDLQ Acoustic measurements and
EODåHQMHKUXSDQDVSORãQR noise abatement in general
91.120.20 $NXVWLNDYVWDYEDK=YRþQD Acoustics in building. Sound
L]RODFLMD insulation
SIST EN ISO 3382-1:2009 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 3382-1:2009
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SIST EN ISO 3382-1:2009
EUROPEAN STANDARD
EN ISO 3382-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2009
ICS 91.120.20 Supersedes EN ISO 3382:2000
English Version
Acoustics - Measurement of room acoustic parameters - Part 1:
Performance spaces (ISO 3382-1:2009)
Acoustique - Mesurage des paramètres acoustiques des Akustik - Messung von raumakustischen Parametern - Teil
salles - Partie 1: Salles de spectacles (ISO 3382-1:2009) 1: Aufführungsplätze (ISO 3382-1:2009)
This European Standard was approved by CEN on 14 June 2009.
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 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 Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 3382-1:2009: E
worldwide for CEN national Members.
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SIST EN ISO 3382-1:2009
EN ISO 3382-1:2009 (E)
Contents Page
Foreword .3
2
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SIST EN ISO 3382-1:2009
EN ISO 3382-1:2009 (E)
Foreword
This document (EN ISO 3382-1:2009) has been prepared by Technical Committee ISO/TC 43 "Acoustics" in
collaboration with Technical Committee CEN/TC 126 “Acoustic properties of building elements and of
buildings” the secretariat of which is held by AFNOR.
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 December 2009, and conflicting national standards shall be withdrawn
at the latest by December 2009.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 3382:2000.
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, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 3382-1:2009 has been approved by CEN as a EN ISO 3382-1:2009 without any modification.
3
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SIST EN ISO 3382-1:2009
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SIST EN ISO 3382-1:2009
INTERNATIONAL ISO
STANDARD 3382-1
First edition
2009-06-15
Acoustics — Measurement of room
acoustic parameters —
Part 1:
Performance spaces
Acoustique — Mesurage des paramètres acoustiques des salles —
Partie 1: Salles de spectacles
Reference number
ISO 3382-1:2009(E)
©
ISO 2009
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SIST EN ISO 3382-1:2009
ISO 3382-1:2009(E)
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Published in Switzerland
ii © ISO 2009 – All rights reserved
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SIST EN ISO 3382-1:2009
ISO 3382-1:2009(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope .1
2 Normative references .1
3 Terms and definitions .1
4 Measurement conditions .3
5 Measurement procedures .6
6 Evaluation of decay curves .8
7 Measurement uncertainty .9
8 Spatial averaging .10
9 Statement of results.10
Annex A (informative) Auditorium measures derived from impulse responses .12
Annex B (informative) Binaural auditorium measures derived from impulse responses .21
Annex C (informative) Stage measures derived from impulse responses.23
Bibliography .25
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SIST EN ISO 3382-1:2009
ISO 3382-1:2009(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 3382-1 was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 2, Building
acoustics.
This first edition of ISO 3382-1, together with ISO 3382-2 and ISO 3382-3, cancels and replaces
ISO 3382:1997, of which it constitutes a technical revision. Annex A has been extended with information on
JND (just noticeable difference), recommended frequency averaging and by the addition of a new parameter
for LEV (listener envelopment). A new Annex C has been added with parameters for the acoustic conditions
on the orchestra platform.
ISO 3382 consists of the following parts, under the general title Acoustics — Measurement of room acoustic
parameters:
⎯ Part 1: Performance spaces
⎯ Part 2: Reverberation time in ordinary rooms
Open plan spaces are to form the subject of a future part 3.
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SIST EN ISO 3382-1:2009
ISO 3382-1:2009(E)
Introduction
The reverberation time of a room was once regarded as the predominant indicator of its acoustical properties.
While reverberation time continues to be regarded as a significant parameter, there is reasonable agreement
that other types of measurements, such as relative sound pressure levels, early/late energy ratios, lateral
energy fractions, interaural cross-correlation functions and background noise levels, are needed for a more
complete evaluation of the acoustical quality of rooms.
This part of ISO 3382 establishes a method for obtaining reverberation times from impulse responses and
from interrupted noise. The annexes introduce the concepts and details of measurement procedures for some
of the newer measures, but these do not constitute a part of the formal specifications of this part of ISO 3382.
The intention is to make it possible to compare reverberation time measurements with higher certainty and to
promote the use of and consensus in measurement of the newer measures.
Annex A presents measures based on squared impulse responses: a further measure of reverberation (early
decay time) and measures of relative sound levels, early/late energy fractions and lateral energy fractions in
auditoria. Within these categories, there is still work to be done in determining which measures are the most
suitable to standardize upon; however, since they are all derivable from impulse responses, it is appropriate to
introduce the impulse response as the basis for standard measurements. Annex B introduces binaural
measurements and the head and torso simulators (dummy heads) required to make binaural measurements
in auditoria. Annex C introduces the support measures that have been found useful for evaluating the acoustic
conditions from the musicians’ point of view.
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SIST EN ISO 3382-1:2009
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SIST EN ISO 3382-1:2009
INTERNATIONAL STANDARD ISO 3382-1:2009(E)
Acoustics — Measurement of room acoustic parameters —
Part 1:
Performance spaces
1 Scope
This part of ISO 3382 specifies methods for the measurement of reverberation time and other room acoustical
parameters in performance spaces. It describes the measurement procedure, the apparatus needed, the
coverage required, and the method of evaluating the data and presenting the test report. It is intended for the
application of modern digital measuring techniques and for the evaluation of room acoustical parameters
derived from impulse responses.
2 Normative references
The following referenced documents are indispensable for the application 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.
IEC 61260, Electroacoustics — Octave-band and fractional-octave-band filters
IEC 61672-1, Electroacoustics — Sound level meters — Part 1: Specifications
3 Terms and definitions
For the purposes of this part of ISO 3382, the following terms and definitions apply.
3.1
decay curve
graphical representation of the decay of the sound pressure level in a room as a function of time after the
sound source has stopped
[ISO 354:2003, 3.1]
NOTE 1 It is possible to measure this decay either after the actual cut-off of a continuous sound source in the room or
derived from the reverse-time integrated squared impulse response of the room (see Clause 5).
NOTE 2 The decay directly obtained after non-continuous excitation of a room (e.g. by recording a gunshot with a level
recorder) is not recommended for accurate evaluation of the reverberation time. This method ought only be used for
survey purposes. The decay of the impulse response in a room is in general not a simple exponential decay, and thus the
slope is different from that of the integrated impulse response.
3.2
interrupted noise method
method of obtaining decay curves by direct recording of the decay of sound pressure level after exciting a
room with broadband or band limited noise
[ISO 354:2003, 3.3]
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SIST EN ISO 3382-1:2009
ISO 3382-1:2009(E)
3.3
integrated impulse response method
method of obtaining decay curves by reverse-time integration of the squared impulse responses
[ISO 354:2003, 3.4]
3.4
impulse response
temporal evolution of the sound pressure observed at a point in a room as a result of the emission of a Dirac
impulse at another point in the room
[ISO 354:2003, 3.5]
NOTE It is impossible in practice to create and radiate true Dirac delta functions, but short transient sounds (e.g. from
gunshots) can offer close enough approximations for practical measurement. An alternative measurement technique,
however, is to use a period of maximum-length sequence (MLS) type signal or other deterministic, flat-spectrum signal like
a sine sweep and transform the measured response back to an impulse response.
3.5
reverberation time
T
〈room acoustic parameters〉 duration required for the space-averaged sound energy density in an enclosure to
decrease by 60 dB after the source emission has stopped
NOTE 1 The reverberation time is expressed in seconds.
NOTE 2 T can be evaluated based on a smaller dynamic range than 60 dB and extrapolated to a decay time of 60 dB.
It is then labelled accordingly. Thus, if T is derived from the time at which the decay curve first reaches 5 dB and 25 dB
below the initial level, it is labelled T . If decay values of 5 dB to 35 dB below the initial level are used, it is labelled T .
20 30
3.6 States of occupancy
3.6.1
unoccupied state
state of a room prepared for use and ready for speakers or for performers and audience, but without these
persons being present, and in the case of concert halls and opera houses, preferably with the performers'
chairs, music stands and percussion instruments, etc.
3.6.2
studio state
〈rooms for speech and music〉 state of a room occupied by performers or speakers only and without an
audience (for example, during rehearsals or sound recordings) and with the number of performers and other
persons such as technicians corresponding to the usual number
3.6.3
occupied state
state of an auditorium or theatre when 80 % to 100 % of the seats are occupied
NOTE Reverberation time measured in a room will be influenced by the number of people present and the above
states of occupancy are defined for measurement purposes.
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SIST EN ISO 3382-1:2009
ISO 3382-1:2009(E)
4 Measurement conditions
4.1 General
The measurements of reverberation time may be made with the room in any or all states of occupancy. Where
the room has adjustable components for providing variable acoustical conditions, it can be relevant to carry
out separate measurements with these components in each of their normal settings. The temperature and
relative humidity of the air in the room should be measured to an accuracy of ± 1 °C and ± 5 %, respectively.
An accurate description of the state of occupancy of the room is of decisive importance in assessing the
results obtained by measuring the reverberation time. Extraordinary occupancies (such as that which would
be created in a concert hall by a larger than usual orchestra or the additional presence of a choir or standees)
shall be noted with the results.
In theatres, a distinction shall be made between “safety curtain up” and “safety curtain down”, between
“orchestra pit open” and “orchestra pit closed”, and also between “orchestra seated on the stage”, with and
without concert enclosure. In all of these cases, measurement can be useful. If the safety curtain is up, the
amount of furnishing of the stage is of importance and shall be described.
Where variable components involve active (i.e. electronic) techniques, the effects of these should be
measured, too, but as certain types of electronic reverberation enhancement systems create non-time-
stationary conditions in the room, a unique impulse response will not exist and caution should be exercised in
using synchronous averaging during the course of making measurements.
4.2 Equipment
4.2.1 Sound source
The sound source shall be as close to omnidirectional as possible (see Table 1). It shall produce a sound
pressure level sufficient to provide decay curves with the required minimum dynamic range, without
contamination by background noise. In the case of measurements of impulse responses using
pseudo-random sequences, the required sound pressure level might be quite low because a strong
improvement of the signal-to-noise ratio by means of synchronous averaging is possible. In the case of
measurements which do not use a synchronous averaging (or other) technique to augment the decay range, a
source level will be required that gives at least 45 dB above the background level in the corresponding
frequency band. If only T is to be measured, it is sufficient to create a level at least 35 dB above the
20
background level.
Table 1 lists the maximum acceptable deviations from omnidirectionality when averaged over “gliding”
30° arcs in a free sound field. In case a turntable cannot be used, measurements per 5° should be performed,
followed by “gliding” averages, each covering six neighbouring points. The reference value shall be
determined from a 360° energetic average in the measurement plane. The minimum distance between source
and microphone shall be 1,5 m during these measurements.
Table 1 — Maximum deviation of directivity of source in decibels for excitation
with octave bands of pink noise and measured in free field
Frequency, hertz
125 250 500 1 000 2 000 4 000
Maximum deviation, decibels
± 1 ± 1 ± 1 ± 3 ± 5 ± 6
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ISO 3382-1:2009(E)
4.2.2 Microphones, recording and analysis equipment
4.2.2.1 General
Omnidirectional microphones shall be used to detect the sound pressure and the output may be taken either
⎯ directly to an amplifier, filter set and a system for displaying decay curves or analysis equipment for
deriving the impulse responses, or
⎯ to a signal recorder for later analysis.
4.2.2.2 Microphone and filters
The measurement equipment shall meet the requirements of a type 1 sound level meter according to
IEC 61672-1. The octave or one-third-octave filters shall conform with IEC 61260. The microphone should be
as small as possible and preferably have a maximum diaphragm diameter of 13 mm. Microphones with
diameters up to 26 mm are allowed, if they are of the pressure response type or of the free field response type
but supplied with a random incidence corrector yielding a flat frequency response at random incidence.
4.2.2.3 Recording device
If the sound decay is initially recorded on magnetic tape or a digital recording device, automatic gain control or
other circuits for dynamic optimization of signal-to-noise ratio shall not be used. The recording time of each
decay shall be sufficiently long to enable determination of the final background level following the decay; five
seconds plus the expected reverberation time is recommended as a minimum.
The recording device shall have the following characteristics for the particular combination of record and
playback speeds used.
a) The frequency response shall be flat over the frequency range of measurement with a smaller tolerance
than ± 3 dB.
b) The dynamic range shall be sufficient to allow the required minimum decay curve range. In the case of
interrupted noise decays, the recorder shall be capable of providing a signal-to-noise ratio of at least
50 dB in every frequency band concerned.
0,1 × n
c) The ratio of the playback speed to the record speed shall be within ± 2 % of 10 , where n is an
integer including zero.
NOTE If speed translation is used on playback, the corresponding frequency translation will then be a whole number
of standard one-third-octave band spacings or, if n is a multiple of three, of octave band spacings.
Where a tape recorder is used, then in respect of the speed of response of the apparatus for forming a record
of the decay of sound pressure level with time (see 4.2.2.4), T refers to the effective reverberation time of the
signal being played back. This will differ from the true reverberation time of the enclosure only if the playback
speed differs from the record speed.
When the decay has been recorded for replay through filters and an integrating device, it can be beneficial to
time-reverse the responses during replay (see Reference [10]).
4.2.2.4 Apparatus for forming decay record of level
The apparatus for forming (and displaying and/or evaluating) the decay record shall use any of the following:
a) exponential averaging, with continuous curve as output;
b) exponential averaging, with successive discrete sample points from the continuous average as output;
c) linear averaging, with successive discrete linear averages as output (in some cases, with small pauses
between performance of averages).
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SIST EN ISO 3382-1:2009
ISO 3382-1:2009(E)
The averaging time, i.e. time constant of an exponential averaging device (or appropriate equivalent), shall be
less than, but as close as possible to, T/30. Similarly, the averaging time of a linear averaging device shall be
less than T/12. Here T is the reverberation time being measured or, if appropriate, the effective reverberation
time as described in the penultimate paragraph of 4.2.2.3.
In apparatus where the decay record is formed as a succession of discrete points, the time interval between
points on the record shall be less than 1,5 times the averaging time of the device.
In all cases where the decay record is to be evaluated visually, adjust the time scale of the display so that the
slope of the record is as close as possible to 45°.
NOTE 1 The averaging time of an exponential averaging device is equal to 4,34 dB [= 10 lg(e)] divided by the decay
rate in decibels per second of the device.
NOTE 2 Commercial level recorders, in which sound pressure level is recorded graphically as a function of time, are
approximately equivalent to exponential averaging devices.
NOTE 3 When an exponential averaging device is used, there is little advantage in setting the averaging time very
much less than T/30. When a linear averaging device is used, there is no advantage in setting the interval between points
at very much less than T/12. In some sequential measuring procedures, it is feasible to reset the averaging time
appropriately for each frequency band. In other procedures, this is not feasible, and an averaging time or interval chosen
as above with reference to the shortest reverberation time in any band has to serve for measurements in all bands.
4.2.2.5 Overload
No overloading shall be allowed in any stage of the measuring apparatus. Where impulsive sound sources are
used, peak-level indicating devices shall be used for checking against overloading.
4.3 Measurement positions
Source positions should be located where the natural sound sources in the room would typically be located. A
minimum of two source positions shall be used. The height of the acoustic centre of the source should be
1,5 m above the floor.
Microphone positions should be at positions representative of positions where listeners would normally be
located. For reverberation time measurements, it is important that the measurement positions sample the
entire space; for the room acoustic parameters described in Annexes A and B, they should also be selected to
provide information on possible systematic variations with position in the room. Microphone positions shall be
at least half a wavelength apart, i.e. a distance of around 2 m for the usual frequency range. The distance
from any microphone position to the nearest reflecting surface, including the floor, shall be at least a quarter of
a wavelength, i.e. normally around 1 m. See A.4 for more details.
No microphone position shall be too close to any source position, in order to avoid a too-strong influence from
the direct sound. In rooms for speech and music, the height of the microphones above the floor should be
1,2 m, corresponding to the ear height of average listeners in typical chairs.
A distribution of microphone positions shall be chosen that anticipates the major influences likely to cause
differences in reverberation time throughout the room. Obvious examples are the differences for seating areas
close to walls, underneath balconies or in spaces which are decoupled (e.g. in church transepts and chancels
compared with church naves). This requires a judgement of the evenness of the “acoustical” distribution to the
different seating areas, the equality of the coupling of the separate parts of the volume and the proximity to
local perturbations.
For reverberation time measurement, it can be useful to assess the room against the following criteria (which
in many cases will simply require a visual assessment) to determine whether single spatial averages will
adequately describe the room:
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SIST EN ISO 3382-1:2009
ISO 3382-1:2009(E)
a) the materials of the boundary surfaces and any suspended elements are such that, judged in terms of
their absorption and diffusion properties, they are reasonably evenly distributed among the surfaces
which surround the room, and
b) all parts of the room volume communicate reasonably equally with each other, in which case three or four
microphone positions will be adequate — these positions being chosen to cover the seating area, in an
evenly spaced array — and the results of the measurements may be averaged.
For a) above, if the ceiling, side, front and rear walls, when assessed individually, have no regions covering
more than 50 % of their respective areas, with properties different from those of the remaining surfaces, then it
may be considered that the distribution is acceptably even (in some spaces it can be helpful to approximate
the room geometry to a rectangular parallelepiped for this assessment).
For b) above, the room volume may be considered to operate as a single space if there are no parts
...