EN 1793-1:2025

SLOVENSKI STANDARD
oSIST prEN 1793-1:2023
01-november-2023
Protihrupne ovire za cestni promet - Preskusna metoda za ugotavljanje akustičnih
lastnosti - 1. del: Karakteristike, značilne za absorpcijo zvoka pri razpršenem
zvočnem polju
Road traffic noise reducing devices - Test method for determining the acoustic
performance - Part 1: Intrinsic characteristics of sound absorption under diffuse sound
field conditions
Lärmschutzvorrichtungen an Straßen - Prüfverfahren zur Bestimmung der akustischen
Eigenschaften - Teil 1: Produktspezifische Merkmale der Schallabsorption in diffusen
Schallfeldern
Dispositifs de réduction du bruit du trafic routier - Méthode d'essai pour la détermination
de la performance acoustique - Partie 1 : Caractéristique intrinsèques de l'absorption
acoustique dans des conditions de champ acoustique diffus
Ta slovenski standard je istoveten z: prEN 1793-1
ICS:
17.140.30 Emisija hrupa transportnih Noise emitted by means of
sredstev transport
93.080.30 Cestna oprema in pomožne Road equipment and
naprave installations
oSIST prEN 1793-1:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 1793-1:2023
oSIST prEN 1793-1:2023
DRAFT
EUROPEAN STANDARD
prEN 1793-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2023
ICS 17.140.30; 93.080.30 Will supersede EN 1793-1:2017
English Version
Road traffic noise reducing devices - Test method for
determining the acoustic performance - Part 1: Intrinsic
characteristics of sound absorption under diffuse sound
field conditions
Dispositifs de réduction du bruit du trafic routier - Lärmschutzvorrichtungen an Straßen - Prüfverfahren
Méthode d'essai pour la détermination de la zur Bestimmung der akustischen Eigenschaften - Teil
performance acoustique - Partie 1 : Caractéristique 1: Produktspezifische Merkmale der Schallabsorption
intrinsèques de l'absorption acoustique dans des in diffusen Schallfeldern
conditions de champ acoustique diffus
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 226.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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-CENELEC
Management Centre has the same status as the official versions.

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Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1793-1:2023 E
worldwide for CEN national Members.

oSIST prEN 1793-1:2023
prEN 1793-1:2023 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Symbols and abbreviations . 7
5 Test arrangement . 8
6 Test procedure and evaluation . 13
6.1 Test method . 13
6.2 Single-number rating of sound absorption DL . 16
α,NRD
7 Measurement uncertainty . 16
8 Test report . 16
Annex A (informative) On the realization of a diffuse sound field . 18
A.1 General . 18
A.2 Additional information on the diffuseness of the sound field in a reverberation room . 18
Annex B (normative) Guidance note on the use of the single-number rating DL . 20
α,NRD
Annex C (normative) Measurement uncertainty . 21
C.1 General . 21
C.2 Measurement uncertainty based upon reproducibility data . 21
C.3 Standard deviation of repeatability and reproducibility of the sound absorption
coefficient . 21
Annex D (normative) Test report template . 23
D.1 Overview . 23
D.2 Test object (example) . 24
D.3 Test situation (example) . 25
D.3.1 Test room and test arrangement . 25
D.3.2 Test equipment and test procedures . 26
D.3.3 Test conditions . 27
D.4 Test results (example) . 27
D.5 Measurement uncertainty (example) . 28
Bibliography . 29

oSIST prEN 1793-1:2023
prEN 1793-1:2023 (E)
European foreword
This document (prEN 1793-1:2023) has been prepared by Technical Committee CEN/TC 226 “Road
equipment”, the secretariat of which is held by AFNOR.
This document will supersede EN 1793-1:2017.
With respect to the superseded document, the following changes have been made:
— ISO/IEC Guide 98-3 and ISO 12999-2 have been added to the References;
— A clause for terms and definitions has been added (new Clause 3);
— An annex has been added explaining the physical hypotheses under the assumption of a diffuse
sound field (Annex A);
— An annex with the values of the standard deviation of reproducibility and repeatability has been
added; this makes possible the declaration of the measurement uncertainty and the related
confidence level, which is now mandatory (Annex C);
— The detailed example has been improved to include the declaration of the uncertainty (Annex D);
— The Bibliography has been updated.
EN 1793-1:2023 is part of a series and should be read in conjunction with the following:
— EN 1793-2:2023, Road traffic noise reducing devices — Test method for determining the acoustic
performance — Part 2: Intrinsic characteristics — Airborne sound insulation under diffuse sound field
conditions;
— EN 1793-3:2023, Road traffic noise reducing devices — Test method for determining the acoustic
performance — Part 3: Normalized traffic noise spectrum;
— EN 1793-4:2023, Road traffic noise reducing devices — Test method for determining the acoustic
performance — Part 4: Intrinsic characteristics — Intrinsic sound diffraction;
— EN 1793-5:2023, Road traffic noise reducing devices — Test method for determining the acoustic
performance — Part 5: Intrinsic characteristics — Sound absorption under direct sound field
conditions;
— EN 1793-6:2023, Road traffic noise reducing devices — Test method for determining the acoustic
performance — Part 6: Intrinsic characteristics — Airborne sound insulation under direct sound field
conditions.
oSIST prEN 1793-1:2023
prEN 1793-1:2023 (E)
Introduction
Where a sound reflecting surface is installed along a road, it may be effective to use sound absorbing
devices on its traffic side to reduce additional noise nuisance caused by reflected sound. This treatment
may be needed in the presence of the following:
— noise barriers, rocks or retaining walls that can reflect sound waves toward unprotected areas;
— vertical cuttings or reflective surfaces that face each other;
— tunnels and their approaches;
— traffic passing close to a barrier where reflections between the vehicles and the barrier may reduce
effectiveness.
This document specifies a test method for qualifying the sound absorption performance of noise
reducing devices designed for roads (a measure of intrinsic performance). It is not concerned with
determining insertion loss (extrinsic performance) which depends on additional factors which are not
related to the product itself, e.g. the dimensions of the barrier and quality of installation work and site
factors such as ground impedance, site geometry etc. The test is designed to allow the intrinsic sound
absorption performance of the device to be measured under diffuse sound field conditions; the
resulting rating should aid the selection of devices for particular roadside applications.
More information on the realization of a diffuse sound field is given in Annex A.
The measurement results of this method for sound absorption are not directly comparable with the
results of the direct sound field method (EN 1793-5), mainly because the present method uses a diffuse
sound field, while the direct sound field method assumes a directional sound field. The test method
described in the present document should not be used to determine the intrinsic characteristics of
sound absorption for noise reducing devices to be installed on roads under non-reverberant conditions.
Research studies suggest that some correlation exists between laboratory data, measured according to
EN 1793-5 [5] and laboratory data, measured according to the method described in this document [1],
[2], [3], [4].
For the purpose of this document, reverberant conditions are defined based on the envelope, e, across
the road formed by the device under test, trench sides or buildings (the envelope does not include the
road surface) as shown by the dashed lines in Figure 1. Conditions are defined as being reverberant
when the percentage of open space in the envelope, w, is less than or equal to 25 %, i.e. reverberant
conditions occur when w/e ≤ 0,25, where e = (w + h + h ) or e = (w + h ) as per Figure 1.
1 2 1
This method may be used to qualify noise reducing devices for other applications, e.g. to be installed
nearby industrial sites. In this case the single-number ratings should be calculated using an appropriate
spectrum.
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prEN 1793-1:2023 (E)
a) Partial cover on both sides of the road; b) Partial cover on one side of the road;
geometric envelope, e = w+h +h geometric envelope, e = w+h
1 2 1
c) Deep trench; d) Tall barriers or buildings;
geometric envelope, e = w+h +h geometric envelope, e = w+h +h
1 2 1 2
Key
r road surface
w width of open space
h developed length of element, e.g. cover, trench side, barrier or building
h developed length of element, e.g. cover, trench side, barrier or building
NOTE Figure 1 is not to scale.
Figure 1 — Sketch of the reverberant condition check in four cases
oSIST prEN 1793-1:2023
prEN 1793-1:2023 (E)
1 Scope
This document specifies the laboratory method for measuring the sound absorption performance of
road traffic noise reducing devices in reverberant conditions. It covers the assessment of the intrinsic
sound absorption performance of devices that can reasonably be assembled inside the testing facility
described in EN ISO 354.
This method is not intended for the determination of the intrinsic characteristics of sound absorption of
noise reducing devices to be installed on roads in non-reverberant conditions.
The test method in EN ISO 354 referred to in this document excludes devices that act as weakly damped
resonators. Some devices will depart significantly from these requirements and in these cases, care is
needed in interpreting the results.
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.
EN 1793-3:2023, Road traffic noise reducing devices - Test method for determining the acoustic
performance - Part 3: Normalized traffic noise spectrum
EN ISO 354:2003, Acoustics - Measurement of sound absorption in a reverberation room (ISO 354:2003)
ISO 9613-1:1993, Acoustics — Attenuation of sound during propagation outdoors — Part 1: Calculation
of the absorption of sound by the atmosphere
ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty
in measurement (GUM:1995)
EN ISO 12999-2:2020, Acoustics - Determination and application of measurement uncertainties in
building acoustics - Part 2: Sound absorption (ISO 12999-2:2020)
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:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
road traffic noise reducing device
RTNRD
device designed to reduce the propagation of traffic noise away from the road environment
Note 1 to entry: An RTNRD can comprise acoustic elements (3.2) only or both structural (3.3) and acoustic
elements.
Note 2 to entry: Applications of RTNRDs include noise barriers (3.5), claddings(3.6), covers (3.7) and added
devices(3.8).
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prEN 1793-1:2023 (E)
3.2
acoustic element
element whose primary function is to provide the acoustic performance of the device
3.3
structural element
element whose primary function is to support or hold in place parts of the RTNRD
3.4
self supporting acoustic element
acoustic element including its own structural element to support itself
3.5
noise barrier
road traffic noise reducing device which obstructs the direct transmission of airborne sound emanating
from road traffic
3.6
cladding
road traffic noise reducing device which is attached to a wall or other structure and reduces the amount
of sound reflected
3.7
cover
road traffic noise reducing device which either spans or overhangs the road
3.8
added device
additional component that influences the acoustic performance of the original road traffic noise
reducing device
Note 1 to entry: The added device is acting primarily on the diffracted energy.
4 Symbols and abbreviations
For the purposes of this document, the following symbols apply.
Table 1 — Symbols and abbreviations
Symbol or Designation Unit
abbreviation
α Sound absorption coefficient -
NRD
A Equivalent sound absorption area of the empty reverberation room m
A Equivalent sound absorption area of the reverberation room containing a test m
specimen
A Equivalent sound absorption area of the test specimen m
T
−1
c Propagation speed of sound in air in the empty reverberation room ms
−1
c Propagation speed of sound in air in the reverberation room with the test ms
specimen during the measurement
oSIST prEN 1793-1:2023
prEN 1793-1:2023 (E)
Symbol or Designation Unit
abbreviation
DL Single-number rating of sound absorption performance expressed as a dB
α,NRD
difference of A weighted sound pressure levels
h Height of reflective frame m
f
i Index of the i-th one-third octave frequency band (between 100 Hz and 5 kHz) -
k Coverage factor -
p
L Length of the test panels on one side of the post m
L Normalized A weighted sound pressure level of traffic noise in the i-th one- dB
i
third octave band defined in EN 1793–3
−1
m Power attenuation coefficient calculated according to ISO 9613-1 using the m
climatic conditions that have been present in the empty reverberation room
during the measurement. The value of m can be calculated from the
attenuation coefficient, α, which is used in ISO 9613-1
−1
m Power attenuation coefficient calculated according to ISO 9613-1 using the m
climatic conditions that have been present in the reverberation room with the
test specimen during the measurement. The value of m can be calculated from
the attenuation coefficient, α, which is used in ISO 9613-1
m Coefficient for calculating the standard deviation of repeatability -
n Term for calculating the standard deviation of repeatability -
S Area (of the floor of the reverberation room) covered by the test specimen m
sr Standard deviation of repeatability -
s Standard deviation of reproducibility -
R
T Reverberation time of the empty reverberation room s
T Reverberation time of the reverberation room after the test specimen has been s
introduced
u Standard uncertainty -
U Expanded uncertainty -
V Net volume of the empty reverberation room m
V Net volume of the reverberation room containing a test specimen m
Vs Net volume of the test sample m
5 Test arrangement
The test arrangement shall be as described in EN ISO 354, with the following modifications.
The test specimen shall be assembled in the test chamber in the same manner as the manufactured
device is used in practice, with the same connections and seals between the component parts.
All the reflecting parts exposed on the road traffic side of the material (posts, brackets and other parts)
shall be present on the specimen as in practice.
Where posts are employed in construction, at least one post shall be included in the specimen with
panels attached on both sides. The length of the panels on one side of the post shall be L ≥ 2 m
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prEN 1793-1:2023 (E)
(Figures 2 and 3). The side that would face the road traffic shall face the inner part of the room
(Figures 2 and 3). The post shall be sealed as in practice.
The test specimen shall have a reflecting frame sealed against it on its entire perimeter and without any
gap between the frame and the surface on which the test specimen is placed (Figures 2 to 6).
The test specimen shall be placed directly against one of the surfaces (floor, wall or ceiling) of the
chamber without any gap (Figures 2, 3 and 4). A dense filling material, such as sand or concrete (density
> 200 kg/m ), shall always be inserted between the panels and chamber surface to completely fill all
gaps.
If the sample under test includes a plenum as part of the design, this shall be reproduced in the
reverberation room and reported in the test report. If the sample under test includes a plenum that is
not a design feature, the plenum shall be completely filled with a dense filling material such as sand or
concrete.
If the sample under test includes a post, it is recommended to cut it to fit the panel thickness.
If the sample under test includes a post having a thickness larger than that of the acoustic elements and
protruding toward the interior of the test chamber, the reflective area created by the post fitting the
acoustic elements shall be reproduced covering it by reflective strips (Figure 5). Alternatively, a T-
shaped element with the same width of reflective surface as the visible face of the post can be used to
replace the post.
If the sample under test includes a post having a thickness larger than that of the acoustic elements and
protruding toward the floor of the test chamber, the cavities created by the post under the acoustic
elements shall be completely filled with a dense filling material such as sand or concrete (Figure 6).
Alternatively, a T-shaped element with the same width of reflective surface as the visible face of the
post can be used to replace the post.
Any combination of the conditions above may be applied in order to be sure that no cavities, gaps or
plenum exist between the sample under test and the chamber surface unless explicitly prescribed for
the device in its normal use.
For testing absorptive cladding for use on retained cuttings, tunnel walls and other reflective surfaces,
the specimen shall be mounted against one of the surfaces of the chamber leaving the same gap and
using the same components as proposed for the actual construction. In this case, the mounting
conditions and components, e.g. the distance between the back of the sample and the surface of the
chamber, shall be clearly reported.

oSIST prEN 1793-1:2023
prEN 1793-1:2023 (E)
Key
1 reflective frame hf height of reflective frame
2 panels L length of the test panels on one side of the post
3 post
4 chamber surface (floor)
5 dense filling material
Figure 2 — Illustration of sample arrangement for devices having visible posts
oSIST prEN 1793-1:2023
prEN 1793-1:2023 (E)
Key
1 reflective frame hf height of reflective frame
2 panels L length of the test panels on one side of the post
3 post
4 chamber surface (floor)
5 dense filling material
Figure 3 — Illustration of a flat sample arrangement having no visible posts and where there are
no designed cavities on the floor/wall facing side of the test sample
oSIST prEN 1793-1:2023
prEN 1793-1:2023 (E)
Key
1 reflective frame 5 dense filling material
2 panels h height of reflective frame
f
3 post L length of the test panels on one side of the post
4 chamber surface (floor)
Figure 4 — Illustration of a non-flat sample arrangement directly against one of the surfaces
(floor, wall or ceiling) of the chamber without any gap

Key
1 reflective frame 5 reflective strips
2 panels 6 dense filling material
3 post hf height of reflective frame
4 chamber surface (floor) L length of the test panels on one side of the post
Figure 5 — Illustration of sample arrangement for devices having posts with a thickness larger
than that of the acoustic elements and protruding toward the interior of the test chamber
oSIST prEN 1793-1:2023
prEN 1793-1:2023 (E)
Key
1 reflective frame 5 dense filling material
2 panels h height of reflective frame
f
3 post L length of the test panels on one side of the post
4 chamber surface (floor)
Figure 6 — Illustration of sample arrangement for devices having posts with a thickness larger
than that of the acoustic elements and protruding toward the floor of the test chamber
6 Test
...