ISO 20189:2018

INTERNATIONAL ISO
STANDARD 20189
First edition
2018-11
Acoustics — Screens, furniture and
single objects intended for interior
use — Rating of sound absorption and
sound reduction of elements based on
laboratory measurements
Acoustique — Meubles, écrans et objets uniques destinés à usage
intérieur — Note de l'absorption acoustique et de réduction
acoustique des éléments basée sur des mesures en laboratoire
Reference number
©
ISO 2018
© ISO 2018
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ii © ISO 2018 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Methods to measure and evaluate various interior acoustic products .3
4.1 Single objects . 3
4.1.1 General. 3
4.1.2 Single object sound absorption . 3
4.2 Desk screens . 4
4.3 Floor screens. 4
4.3.1 General. 4
4.3.2 Floor screen sound absorption . 4
4.3.3 Floor screen sound attenuation . 4
4.3.4 Floor screen sound insulation . 4
4.4 Furniture ensembles . 5
4.4.1 General. 5
4.4.2 Furniture ensembles sound absorption . 5
2 5
4.5 Single objects that are tightly connected to form a surface greater than or equal to 10 m
4.6 Other single objects . 5
5 Statement of results . 5
5.1 Results for sound absorption . 5
5.2 Results for floor screen sound attenuation . 5
5.3 Results for sound insulation . 6
5.4 Other information to be reported . 6
Annex A (normative) Presentation of equivalent sound absorption area . 7
Annex B (normative) Examples for the deduction of object sound absorption coefficient, α .9
obj
Annex C (normative) Presentation of floor screen sound attenuation .14
Annex D (normative) Presentation of screen sound insulation .15
Annex E (normative) Mounting conditions in the laboratory .17
Annex F (informative) Guidelines on suitable values for sound insulation for different
screen heights .27
Bibliography .28
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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electrotechnical standardization.
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described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
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This document was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 2, Building
acoustics.
Any feedback or questions on this document should be directed to the user’s national standards body. A
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iv © ISO 2018 – All rights reserved

Introduction
The interior design industry is progressing rapidly, and the acoustic characteristics of products have
become an important technical aspect in the design of new products. Currently, interior design products
are generally not well defined in terms of their acoustic characteristics, often leading to confusing and
misleading product specifications and marketing materials. Further, it is often unclear how a product’s
reported acoustic characteristics are to be applied to determine its acoustic impact in a furnished room.
This document is intended to clarify the acoustic characteristics, and their application, for various
interior design products. This is accomplished by a standardized test methodology for the measurement
of sound absorption, and defining when an interior product is to be considered as a single object.
This document is intended to facilitate the measurement and evaluation procedure for any interior
product currently on the market. By using it, different interior design products can be compared to
each other in an equal manner. Additionally, product acoustic characteristics evaluated according to
this document can be applied for room acoustic modelling and calculations.
INTERNATIONAL STANDARD ISO 20189:2018(E)
Acoustics — Screens, furniture and single objects intended
for interior use — Rating of sound absorption and sound
reduction of elements based on laboratory measurements
1 Scope
This document specifies how screens, furniture and single objects intended for interior use are assessed
with regard to sound absorption and specifies the evaluation of sound attenuation for floor screens. It
also specifies under which circumstances various interior products for offices, schools and other public
spaces are considered as plane absorbers or as discrete single objects. A product considered as a single
object and intended for interior use is measured according to ISO 354 and evaluated by its equivalent
sound absorption area or object sound absorption coefficient in octave bands. This document defines
interior products and single objects and it comprises additional information regarding measurements
and assessment of single objects.
The sound absorption as specified in this document can be used to calculate:
a) reverberation time characteristics in rooms;
b) room acoustic parameters using ray tracing software.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
ISO 354:2003, Acoustics — Measurement of sound absorption in a reverberation room
ISO 717-1:2013, Acoustics — Rating of sound insulation in buildings and of building elements — Part 1:
Airborne sound insulation
ISO 10053, Acoustics — Measurement of office screen sound attenuation under specific laboratory
conditions
ISO 10140-2, Acoustics — Laboratory measurement of sound insulation of building elements — Part 2:
Measurement of airborne sound insulation
ISO 11654:1997, Acoustics — Sound absorbers for use in buildings — Rating of sound absorption
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
interior acoustic product
object aimed for insertion loss and/or absorption of indoor sound
3.2
single object
interior acoustic product (3.1) with a defined size and normally mounted by itself, i.e. at some distance
to the nearest other single object
Note 1 to entry: Single objects are sometimes mounted tightly together to form an array or a large homogeneous
surface. Single objects do not have the same acoustic performance when considered in larger groups.
3.3
desk screen
single object (3.2) intended to be mounted vertically on the side of a table top
3.4
floor screen
single object (3.2) intended to stand vertically on the floor
3.5
furniture ensemble
setup of furniture and screens, connected sofas, or any other combination considered as a single
object (3.2)
3.6
equivalent sound absorption area per single object
A
obj
frequency-dependent value for the equivalent sound absorption area
Note 1 to entry: Measurements are carried out according to ISO 354. When the test specimen comprises several
identical single objects, A is found by dividing A (equivalent sound absorption area of the test specimen as
obj T
defined in ISO 354) by the number of single objects.
Note 2 to entry: It is used to describe a single object’s ability to absorb sound.
Note 3 to entry: The unit is absorption area in m .
3.7
practical sound absorption coefficient
α
p
frequency-dependent value of the sound absorption coefficient which is based on measurements on
one-third-octave bands in accordance with ISO 354 and which is calculated in octave bands
[SOURCE: ISO 11654:1997, 3.1, modified — “in accordance with this International Standard” and Note 1
to entry have been deleted.]
3.8
weighted sound absorption coefficient
α
w
frequency weighted single number value evaluated from the practical sound absorption coefficients (3.7)
Note 1 to entry: The weighting procedure is described in ISO 11654.
3.9
single object’s absorption coefficient
α
obj
single object (3.2)’s frequency-dependent absorption coefficient in octave bands (for use in 3D
simulations) based on the product’s equivalent sound absorption area, A (3.6)
obj
Note 1 to entry: Examples of evaluation are given in Annex B.
2 © ISO 2018 – All rights reserved

3.10
screen sound attenuation
ΔL
s
floor screen (3.4) sound attenuation in different octave bands
Note 1 to entry: Measurements are carried out according to ISO 10053.
Note 2 to entry: For a screen with no air gap at the floor, ΔL is an approximation of the insertion loss that would
s
have been obtained in a free field with a corresponding screen of infinite width and semi-infinite height.
3.11
weighted screen sound attenuation
ΔL
s,w
single number value of the screen sound attenuation (3.10) weighted and evaluated from the measured
octave band values
Note 1 to entry: The weighting procedure is described in ISO 10053.
3.12
sound reduction index
R
frequency-dependent measure describing how much sound energy is transmitted through a screen
construction
Note 1 to entry: Measurements are carried out according to ISO 10140-2.
3.13
weighted sound reduction index
R
w
frequency weighted value evaluated from the frequency-dependent sound reduction indexes (3.12)
Note 1 to entry: The weighting procedure is described in ISO 717-1.
Note 2 to entry: Annex F gives additional information on which weighted sound reduction index it is reasonable
to strive for depending on the screen height.
4 Methods to measure and evaluate various interior acoustic products
4.1 Single objects
4.1.1 General
Single objects are typically floor screens, desk screens, chairs, stools, desks, sofas or any other object
that can absorb, scatter or spread sound within a room. They can also be unique products intended for
wall application or for interior decoration, which have an added room acoustic effect.
Single objects are normally measured, evaluated and declared with regard to their sound absorption
characteristics. For specific product categories or mounting conditions, additional acoustic
characteristics may be measured and evaluated (see 4.3 and 4.5).
4.1.2 Single object sound absorption
The sound absorption of a single object is measured according to ISO 354 while additional specified
mounting conditions are given in Annex E. The sound absorption of the object shall be given as the
equivalent sound absorption area, A , in the 1/3-octave bands between 100 Hz and 5 000 Hz and in
obj
the octave bands 125 Hz, 250 Hz, 500 Hz, 1 000 Hz, 2 000 Hz and 4 000 Hz, calculated according to
Formula (1):
AA++A
()
obj,k1 obj,k2 obj,k3
A = (1)
obj,k
where A is the centre frequency of the 1/3-octave band within each k-th octave band. Hence, for a
obj,kl
single object, the practical and weighted sound absorption coefficients are not evaluated (ISO 11654).
However, the single object’s sound absorption coefficient, α , may be evaluated in addition to the
obj
single object’s sound absorption, A . The procedure to evaluate α in octave bands (weighted value is
obj obj
not allowed) is given in Annex B.
4.2 Desk screens
Desk screens and similar single objects are measured and evaluated with regard to their sound
absorption characteristics. The sound absorption of desk screens is measured according to 4.1.2 and
evaluated according to Formula (1).
4.3 Floor screens
4.3.1 General
A floor screen is a room divider normally used in large rooms to provide sound attenuation between
workstations or different zones with several workstations. A floor screen can have different heights
and is normally comprised of several units standing on the floor, connected to create a space separation
around one or more workstations. Single screen units can occur but are then not regarded as a screen
but instead as a single object. A floor screen is normally higher than 1,4 m but lower than room height,
leaving some space between the ceiling and its top.
Floor screens can be measured, evaluated and declared with regard to their sound absorption
characteristics, their screen sound attenuation and sound insulation (sound reduction index).
4.3.2 Floor screen sound absorption
The sound absorption of a floor screen is measured according to 4.1.2 and evaluated according to
Formula (1).
4.3.3 Floor screen sound attenuation
The sound attenuation of a floor screen is given as ΔL , and ΔL according to ISO 10053. The values are
s s,w
strongly dependent on the actual screen height and connections between units, and are therefore only
applicable for the screen height and the connection setup that were valid during the measurements.
4.3.4 Floor screen sound insulation
The sound insulation of a floor screen is denoted with the frequency-dependent sound reduction
index, R, and with the weighted sound reduction index, R . The sound reduction index is measured
w
in a laboratory where the screen construction is mounted in the entire test opening according to
ISO 10140-2. The sound reduction index is measured for the entire construction including connections
to floor, walls and between individual screen elements. Connections between screen elements shall
be performed as it is done in reality (normally). No extra sealing is allowed between adjacent screen
elements. An edge of maximum 5 cm is allowed around the test specimen in order to simplify the
mounting.
The sound reduction shall be measured in the 1/3-octave bands between 100 Hz and 5 000 Hz. The
frequency range may be extended in order to comprise frequencies between 50 Hz, if possible.
4 © ISO 2018 – All rights reserved

4.4 Furniture ensembles
4.4.1 General
A furniture ensemble is a determined setup of a fixed set of interior products and furniture that creates
a composite object, a combination of a desk with screens forming a workplace, a telephone booth, or
similar. Furniture ensembles are normally aimed at creating a workstation with privacy and reducing
speech transmission from the ensemble to the surroundings.
4.4.2 Furniture ensembles sound absorption
The sound absorption of a furniture ensemble is measured according to 4.1.2 and evaluated according
to Formula (1).
4.5 Single objects that are tightly connected to form a surface greater than or equal
to 10 m
Sound-absorbing single objects that are tightly connected forming a homogeneous surface larger than
or equal to 10 m are defined as large absorbing surfaces aimed to be applied on walls or any other
plane surface. The sound absorption is then defined by the practical sound absorption coefficient
according to ISO 11654.
4.6 Other single objects
Any other single object such as lamps, lighting devices, others 3D-objects, art objects, etc. that cannot
be classified as defined in 4.2 to 4.5 shall be treated according to 4.1.2.
5 Statement of results
5.1 Results for sound absorption
The test specimen including the interior product shall be described, including its mounting conditions.
It shall be clearly stated how the sound absorbing surfaces (if any) and frames are distributed on the
tested objects.
The test conditions shall be indicated, including the number of objects in the test specimen and their
locations in the reverberation chamber. The volume of the reverberation chamber and its treatment
with diffusors shall be given in the report, as described in ISO 354. Mounting conditions for various test
specimen are given in Annex E.
The test specimen shall meet the requirements for sample sizes in ISO 354. If any deviations occur, an
explanation shall be given as to why they have been made.
α can be evaluated for the product, if applicable. The use of α and α is only allowed for single objects
obj p w
that are tightly connected to form a surface greater than 10 m , as specified in 4.5.
5.2 Results for floor screen sound attenuation
The test specimen including the interior product shall be described, including measurement and
mounting preconditions according to the rules given in ISO 10053. All connections between screen
elements and mounting conditions shall be presented.
Any deviations from ISO 10053 shall be reported including an explanation on why they have been made.
5.3 Results for sound insulation
The test specimen including the product shall be described, including measurement and mounting
preconditions according to the rules given in ISO 10140-2. All connections between screen elements
and mounting conditions shall be presented.
Potential deviations from ISO 10140-2 shall be reported including an explanation on why they have
been made.
5.4 Other information to be reported
The test report shall also include:
a) the name and address of the laboratory that has performed the measurements;
b) the identification number of the test/evaluation report;
c) the name and address of the organization that has ordered the measurement and the evaluation;
d) the name and address of the manufacturer of the tested product;
e) the name or any other identification of the tested product;
f) a detailed description of the test specimen, including the specimen's dimensions;
g) the date when the test was carried out;
h) measurement information according to the specifications in ISO 354;
i) test results according to:
1) Annex A for measurement of equivalent sound absorption area of single objects, including
mounting conditions according to Annex E;
2) Annex B for evaluation of α (if applicable);
obj
3) Annex C for measurement of screen sound attenuation of floor screens (if applicable),
ISO 10053;
4) Annex D for measurement of sound reduction of a screen (if applicable);
5) ISO 11654 for measurement of draperies, curtains and an array of single objects or tightly
connected to surfaces with a size larger than or equal to 10 m ;
j) the date and signature of the person who was responsible for the test;
k) a reference to this document, i.e. ISO 20189:2018.
6 © ISO 2018 – All rights reserved

Annex A
(normative)
Presentation of equivalent sound absorption area
The equivalent sound absorption area per single object is presented as given in Table A.1 and Figure A.1
in m according to the following:
a) In the 1/3 octave bands from 100 Hz to 5 000 Hz, the values shall be rounded to 0,1 m . Data from
the 1/3 octave bands 50 Hz, 63 Hz and 80 Hz are optional.
b) In the octave bands between 125 Hz to 4 000 Hz, the values shall be rounded to 0,1 m . However, if
the highest measured equivalent sound absorption area is less than 1,0 m , two decimals shall be
applied for all octave bands. Data from the octave band 63 Hz is optional.
NOTE 1 This is not contradictory to the measurement uncertainty of ISO 354 since there is a requirement in
ISO 354 regarding the minimum added equivalent sound absorption area. If the objects have small equivalent
sound absorption areas, more objects are needed in the test specimen compared to objects with large equivalent
sound absorption area.
NOTE 2 It is important to be aware of the high uncertainty in the results from 63 Hz.
Table A.1 — Example of presentation of equivalent sound absorption area
Equivalent sound absorption area/object
1/3 octave band
m
Hz
1/3 octave band octave band
50 Optional
63 Optional Optional
80 Optional
100 0,4
125 0,5 0,5
160 0,6
200 0,6
250 0,9 0,9
315 1,2
400 1,1
500 1,2 1,2
630 1,3
800 1,4
1 000 1,6 1,6
1 250 1,8
1 600 1,8
2 000 1,6 1,6
2 500 1,4
3 150 1,4
4 000 1,4 1,4
5 000 1,4
Key
X frequency, in Hz
Y equivalent sound absorption area, in m
Figure A.1 — Example of presentation of equivalent sound absorption area
8 © ISO 2018 – All rights reserved

ISO 20
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