SIST EN 16272-4:2016

Railway applications - Track - Noise barriers and related devices acting on airborne sound propagation - Test method for determining the acoustic performance - Part 4: Intrinsic characteristics - In situ values of sound diffraction under direct sound field conditions

This European Standard describes a test method for determining the intrinsic characteristics of sound diffraction of added devices installed on the top of railway noise barriers. The test method prescribes measurements of the sound pressure level at several reference points near the top edge of a noise barrier with and without the added device installed on its top. The effectiveness of the added device is calculated as the difference between the measured values with and without the added devices, correcting for any change in height (the method described gives the acoustic benefit over a simple barrier of the same height; however, in practice the added device can raise the height and this would provide additional screening depending on the source and receiver positions).

Bahnanwendungen - Oberbau - Lärmschutzwände und verwandte Vorrichtungen zur Beeinflussung der Luftschallausbreitung - Prüfverfahren zur Bestimmung der akustischen Eigenschaften - Teil 4: Produktspezifische Merkmale - In-situ-Werte von Schallbeugung in direkten Schallfeldern

Diese Europäische Norm beschreibt ein Prüfverfahren zur Bestimmung der produktspezifischen Merkmale der Schallbeugung von Wandaufsätzen, die auf den oberen Rand von Eisenbahn-Lärmschutzwänden aufgesetzt werden. Das Prüfverfahren schreibt Messungen des Schalldruckpegels an verschiedenen Bezugspunkten nahe der Oberkante einer Lärmschutzwand mit und ohne Wandaufsätze vor. Die Wirksamkeit der Wandaufsätze berechnet sich als Differenz der mit und ohne Wandaufsatz gemessenen Werte unter Korrektur jedweder Veränderung der Höhe. In anderen Worten, die beschriebene Methode liefert den akustischen Vorteil durch die Veränderung der Form und des Materials an der Oberkante gegenüber einer einfachen Lärmschutzwand derselben Höhe. Dies ist ein produktspezifisches Merkmal des Wandaufsatzes, vorausgesetzt die Schallquellen- und Empfängerpositionen sind standardisiert. In der Praxis, wenn der Wandaufsatz oberhalb der Lärmschutzwand angebracht ist, vergrößert sich die Höhe, und dies führt zu zusätzlicher Abschirmung in Abhängigkeit der Schallquellen- und Empfängerpositionen, dies ist nicht in dieser Europäischen Norm berücksichtigt.
Das Prüfverfahren ist für die folgenden Anwendungen vorgesehen:
-   im Freien oder in Räumen erfolgende Vorprüfung von Wandaufsätzen, die auf Lärmschutzwände montiert werden sollen;
-   Bestimmung der Schallbeugungsindex-Differenz von Wandaufsätzen im tatsächlichen Gebrauch;
-   Vergleich zwischen Bemessungsdaten eines Wandaufsatzes mit tatsächlichen Leistungsdaten nach der Vollendung des Bauwerks;
-   Nachprüfung der Langzeitwirksamkeit von Wandaufsätzen (mit wiederholter Anwendung des Verfahrens);
-   interaktiver Gestaltungsprozess für neue Produkte einschließlich Formulierung von Aufbauanleitungen.
Das Prüfverfahren kann sowohl in situ als auch an eigens für die Prüfung nach dem hier beschriebenen Verfahren hergestellten Prüfkörpern angewandt werden.
Die Ergebnisse werden als Funktion der Frequenz in Terzbändern zwischen 100 Hz und 5 kHz angegeben. Wenn keine gültigen Messergebnisse über den gesamten angegebenen Frequenzbereich zu erhalten sind, sind die Ergebnisse im eingeschränkten Frequenzbereich anzugeben und die Gründe für die Einschränkung(en) klar anzugeben. Eine Einzahl-Angabe wird von den frequenzabhängigen Werten abgeleitet.
Für Messungen im Innenraum siehe Anhang A.

Applications ferroviaires - Voie - Dispositifs de réduction du bruit - Méthode d'essai pour la détermination des performances acoustiques - Partie 4: Caractéristiques intrinsèques - Valeurs in situ de la diffraction acoustique dans des conditions de champ acoustique direct

La présente Norme européenne décrit une méthode d'essai permettant de déterminer les caractéristiques intrinsèques de la diffraction acoustique des couronnements installés au sommet des écrans antibruit le long des voies ferrées. La méthode d'essai prescrit des mesures du niveau de pression acoustique en plusieurs points de référence situés à proximité du bord supérieur d'un écran antibruit, avec et sans le couronnement installé au sommet. L'efficacité intrinsèque du couronnement est calculée comme la différence entre les valeurs mesurées avec et sans le couronnement, en appliquant une correction pour toute variation de hauteur. En d’autres termes, la méthode décrite ici donne le bénéfice acoustique par rapport à un simple écran de même hauteur ; C’est une caractéristique intrinsèque du couronnement, à condition que les positions de la source et du récepteur soient normalisés. En pratique, le couronnement augmente la hauteur et cela constitue un écran supplémentaire selon les positions de la source et du récepteur ; cet écran supplémentaire n’est pas pris en compte dans la présente Norme européenne.
La méthode d'essai est destinée aux applications suivantes :
   qualification préliminaire, à l'extérieur ou à l'intérieur, de couronnements devant être installés sur des écrans antibruit ;
   détermination de la différence d'indice de diffraction acoustique des couronnements en service ;
   comparaison des spécifications de conception d'un couronnement avec des données de performance réelles de l'ouvrage de construction achevé ;
   vérification des performances à long terme de couronnements (par l'application répétée de la méthode) ;
   processus interactif de conception de nouveaux produits, y compris la formulation des manuels d'installation.
La méthode d'essai peut être appliquée aussi bien in situ que sur des échantillons construits spécifiquement pour être soumis à l'essai en utilisant la méthode décrite dans le présent document.
Les résultats sont exprimés en fonction de la fréquence, par bandes de tiers d'octave entre 100 Hz et 5 kHz. S'il est impossible d'obtenir des résultats de mesure valables sur toute la gamme de fréquences indiquée, les résultats doivent être donnés pour la gamme de fréquences réduite et les raisons de la (des) restriction(s) doivent être clairement consignées. Un indice unique d'évaluation est calculé à partir des données de fréquence.
Pour les mesures effectuées à l'intérieur, voir l'Annexe A.

Železniške naprave - Zgornji ustroj proge - Protihrupne ovire in pripadajoče naprave, ki vplivajo na širjenje zvoka v zraku - Preskusna metoda za ugotavljanje akustičnih lastnosti - 4. del: Specifične karakteristike - Terenske vrednosti difrakcije zvoka pri usmerjenem zvočnem polju

Ta evropski standard opisuje preskusno metodo za ugotavljanje specifičnih karakteristik difrakcije zvoka dodanih ovir, nameščenih na protihrupne ovire za železniški promet. Preskusna metoda predpisuje meritve ravni zvočnega tlaka na različnih referenčnih točkah blizu zgornjega roba protihrupne ovire z dodano oviro ali brez nje. Učinkovitost dodane ovire se izračuna kot razlika med izmerjenimi vrednostmi z dodanimi ovirami ali brez njih, s korekcijo sprememb višine (opisana metoda podaja akustične prednosti preproste ovire z isto višino, vendar lahko v praksi dodana ovira presega višino, kar omogoča dodatno zaslonitev glede na položaj vira in sprejemnika).

General Information

• Status: Published
• Public Enquiry End Date: 10-Aug-2014
• Publication Date: 09-Oct-2016
• ICS: 17.140.30 - Noise emitted by means of transport
• ICS: 93.100 - Construction of railways
• Technical Committee: IŽNP - Reilway applications
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 05-Oct-2016
• Due Date: 10-Dec-2016
• Completion Date: 10-Oct-2016
• Mandate: M/024 - Mandate to CEN/CENELEC/ETSI for programming and standardization in the field of railway equipment
• Ref Project: EN 16272-4:2016 - Railway applications - Track - Noise barriers and related devices acting on airborne sound propagation - Test method for determining the acoustic performance - Part 4: Intrinsic characteristics - In situ values of sound diffraction under direct sound field

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 16272-4:2016
01-november-2016
äHOH]QLãNHQDSUDYH=JRUQMLXVWURMSURJH3URWLKUXSQHRYLUHLQSULSDGDMRþH
QDSUDYHNLYSOLYDMRQDãLUMHQMH]YRNDY]UDNX3UHVNXVQDPHWRGD]DXJRWDYOMDQMH
DNXVWLþQLKODVWQRVWLGHO6SHFLILþQHNDUDNWHULVWLNH7HUHQVNHYUHGQRVWL
GLIUDNFLMH]YRNDSULXVPHUMHQHP]YRþQHPSROMX
Railway applications - Track - Noise barriers and related devices acting on airborne
sound propagation - Test method for determining the acoustic performance - Part 4:
Intrinsic characteristics - In situ values of sound diffraction under direct sound field
conditions
Bahnanwendungen - Oberbau - Lärmschutzwände und verwandte Vorrichtungen zur
Beeinflussung der Luftschallausbreitung - Prüfverfahren zur Bestimmung der
akustischen Eigenschaften - Teil 4: Produktspezifische Merkmale - In-situ-Werte von
Schallbeugung in direkten Schallfeldern
Applications ferroviaires - Voie - Dispositifs de réduction du bruit - Méthode d'essai pour
la détermination des performances acoustiques - Partie 4: Caractéristiques intrinsèques -
Valeurs in situ de la diffraction acoustique dans des conditions de champ acoustique
direct
Ta slovenski standard je istoveten z: EN 16272-4:2016
ICS:
17.140.30 Emisija hrupa transportnih Noise emitted by means of
sredstev transport
93.100 Gradnja železnic Construction of railways
SIST EN 16272-4:2016 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 16272-4:2016

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SIST EN 16272-4:2016


EN 16272-4
EUROPEAN STANDARD

NORME EUROPÉENNE

September 2016
EUROPÄISCHE NORM
ICS 93.100
English Version

Railway applications - Track - Noise barriers and related
devices acting on airborne sound propagation - Test
method for determining the acoustic performance - Part 4:
Intrinsic characteristics - In situ values of sound diffraction
under direct sound field
Applications ferroviaires - Voie - Dispositifs de Bahnanwendungen - Oberbau - Lärmschutzwände und
réduction du bruit - Méthode d'essai pour la verwandte Vorrichtungen zur Beeinflussung der
détermination des performances acoustiques - Partie Luftschallausbreitung - Prüfverfahren zur Bestimmung
4: Caractéristiques intrinsèques - Valeurs in situ de la der akustischen Eigenschaften - Teil 4:
diffraction acoustique dans des conditions de champ Produktspezifische Merkmale - In -situ -Werte zur
acoustique direct Schallbeugung in gerichteten Schallfeldern
This European Standard was approved by CEN on 25 March 2016.

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-CENELEC 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-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 16272-4:2016 E
worldwide for CEN national Members.

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SIST EN 16272-4:2016
EN 16272-4:2016 (E)
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Symbols and abbreviations . 9
5 Sound diffraction index difference measurements . 10
5.1 General principle . 10
5.2 Dimensions and specifications . 15
5.2.1 Added devices . 15
5.2.2 Reference walls . 15
5.2.3 In situ tests . 16
5.3 Positions of the sound source . 16
5.4 Position of the microphone(s) . 16
5.5 Free-field measurements . 17
5.6 Measured quantity . 18
5.7 Measuring equipment . 18
5.7.1 Components of the measuring system . 18
5.7.2 Sound source . 20
5.7.3 Test signal . 20
5.8 Data processing . 20
5.8.1 Calibration . 20
5.8.2 Sample rate . 21
5.8.3 Background noise . 21
5.8.4 Measurement points . 21
5.8.5 Adrienne temporal window . 21
5.8.6 Placement of the Adrienne temporal window . 22
5.8.7 Low frequency limit and sample size . 24
5.9 Positioning of the measuring equipment . 24
5.9.1 Selection of the measurement positions. 24
5.9.2 Reflecting objects . 25
5.9.3 Safety considerations. 25
5.10 Sound diffraction index difference . 25
5.11 Sample surface and meteorological conditions . 25
5.11.1 Condition of the sample surface . 25
5.11.2 Wind . 26
5.11.3 Air temperature . 26
6 Measurement uncertainty . 26
7 Measuring procedure . 26
8 Test report . 27
8.1 Expression of results . 27
8.2 Further information . 27
2

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EN 16272-4:2016 (E)
Annex A (informative) Indoor measurements for product qualification . 29
A.1 General . 29
A.2 Parasitic reflections . 29
A.3 Reverberation time of the room . 29
Annex B (informative) Measurement uncertainty . 31
B.1 General . 31
B.2 Expression for the calculation of sound diffraction index . 31
B.3 Contributions to measurement uncertainty . 32
B.4 Expanded uncertainty of measurement . 33
B.5 Measurement uncertainty based upon reproducibility data . 33
Bibliography . 34

3

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SIST EN 16272-4:2016
EN 16272-4:2016 (E)
European foreword
This document (EN 16272-4:2016) has been prepared by Technical Committee CEN/TC 256 “Railway
applications”, the secretariat of which is held by DIN.
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 March 2017, and conflicting national standards shall
be withdrawn at the latest by March 2017.
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 European Standard is one of the series EN 16272 “Railway applications – Track – Noise barriers and
related devices acting on airborne sound propagation – Test method for determining the acoustic
performance” as listed below:
— Part 1: Intrinsic characteristics – Sound absorption in the laboratory under diffuse sound field
conditions
— Part 2: Intrinsic characteristics – Airborne sound insulation in the laboratory under diffuse sound field
conditions
— Part 3-1: Normalized railway noise spectrum and single number ratings for diffuse field applications
— Part 3-2: Normalized railway noise spectrum and single number ratings for direct field applications
— Part 4: Intrinsic characteristics – In situ values of sound diffraction under direct sound field conditions
— Part 5: Intrinsic characteristics – In situ values of sound reflection under direct sound field conditions
— Part 6: Intrinsic characteristics – In situ values of airborne sound insulation under direct sound field
conditions
— Part 7: Extrinsic characteristics – In situ values of insertion loss
This document should be read in conjunction with:
— EN 16272-3-2, Railway applications – Track – Noise barriers and related devices acting on airborne
sound propagation – Test method for determining the acoustic performance – Part 3-2: Normalized
railway noise spectrum and single number ratings for direct field applications
— EN 16272-6, Railway applications – Track – Noise barriers and related devices acting on airborne
sound propagation – Test method for determining the acoustic performance – Part 6: Intrinsic
characteristics – In situ values of airborne sound insulation under direct sound field conditions
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,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
4

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SIST EN 16272-4:2016
EN 16272-4:2016 (E)
Introduction
Part of the market for railway noise barriers and related devices acting on airborne sound propagation
includes products to be added to the top of noise barriers and intended to contribute to sound
attenuation acting primarily on the diffracted sound field. These products are called here “added
devices”. This standard has been developed to specify a test method for determining the acoustic
performance of added devices.
The test method can be applied in situ, i.e. where the railway noise barriers and the added devices are
installed. The method can be applied without damaging the railway noise barriers or the added devices.
The method can be used to qualify products before the installation along railways as well as to verify
the compliance of installed added devices to design specifications. Repeated application of the method
can be used to verify the long term performance of added devices.
This method could be used to qualify added devices for other applications, e.g. to be installed along
roads or nearby industrial sites. In this case, special care has to be taken in considering the location of
the noise sources and the single-number ratings should be calculated using an appropriate spectrum.
No other national or international standard exists about the subject of this standard.
5

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EN 16272-4:2016 (E)
1 Scope
This European Standard describes a test method for determining the intrinsic characteristics of sound
diffraction of added devices installed on the top of railway noise barriers. The test method prescribes
measurements of the sound pressure level at several reference points near the top edge of a noise
barrier with and without the added device installed on its top. The intrinsic effectiveness of the added
device is calculated as the difference between the measured values with and without the added devices,
correcting for any change in height. In other words, the method described here gives the acoustic
benefit of changing the shape and materials of the top edge over a simple barrier of the same height.
This is an intrinsic characteristic of the added device, provided that the source and receiver positions
are standardized. In practice, when the added device is placed over an existing barrier, it raises the
height and this provides additional screening, depending on the source and receiver positions; this
additional screening is not considered in this European Standard.
The test method is intended for the following applications:
— preliminary qualification, outdoors or indoors, of added devices to be installed on noise barriers;
— determination of the sound diffraction index difference of added devices in actual use;
— comparison of design specifications of an added device with actual performance data after the
completion of the construction work;
— verification of the long term performance of added devices (with a repeated application of the
method);
— interactive design process of new products, including the formulation of installation manuals.
The test method can be applied both in situ and on samples purposely built to be tested using the
method described here.
Results are expressed as a function of frequency, in one-third octave bands between 100 Hz and 5 kHz.
If it is not possible to get valid measurements results over the whole frequency range indicated, the
results shall be given in the restricted frequency range and the reasons for the restriction(s) shall be
clearly reported. A single-number rating is calculated from frequency data.
For indoor measurements, see Annex A.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN 16272-3-2, Railway applications — Track — Noise barriers and related devices acting on airborne
sound propagation — Test method for determining the acoustic performance — Part 3-2: Normalized
railway noise spectrum and single number ratings for direct field applications
EN 16272-6, Railway applications — Track — Noise barriers and related devices acting on airborne
sound propagation — Test method for determining the acoustic performance — Part 6: Intrinsic
characteristics — In situ values of airborne sound insulation under direct sound field conditions
EN ISO 354, Acoustics — Measurement of sound absorption in a reverberation room (ISO 354)
EN 61672-1, Electroacoustics — Sound level meters — Part 1: Specifications (IEC 61672-1)
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EN 16272-4:2016 (E)
ISO/IEC Guide 98-3, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
measurement (GUM:1995)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
noise barrier
noise reducing device, which obstructs the direct transmission of airborne sound emanating from
railways; it will typically span between posts and also may overhang the railway
Note 1 to entry: Noise barriers are generally made of acoustic and structural elements (3.3 and 3.4).
3.2
cladding
noise reducing device, which is attached to a wall or other structure and reduces the amount of sound
reflected
Note 1 to entry: Claddings are generally made of acoustic and structural elements (3.3 and 3.4).
3.3
acoustic element
element whose primary function is to provide the acoustic performance of the device
3.4
structural element
element whose primary function is to support or hold in place acoustic elements
Note 1 to entry: In some noise barriers, the acoustic function and the structural function cannot be clearly
separated and attributed to different components.
3.5
added device
added component that influences the acoustic performance of the original noise-reducing device (acting
primarily on the diffracted energy)
3.6
rail side exposure
use of the product as a noise reducing device installed alongside railways
3.7
sound diffraction index, DI
result of a sound diffraction test whose components are described by the formula in 5.6
Note 1 to entry: DI refers to measurements on a reflective reference wall. DI refers to measurements on
x,refl x,abs
an absorptive reference wall. DI refers to in situ measurements; where x is “0” when the added device is not on
x,situ
the top of the test construction and “ad” when the added device is on the top of the test construction
3.8
sound diffraction index difference, DDI
difference between the results of sound diffraction tests on the same reference wall with and without
an added device on the top, described by the formulae in 5.10
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EN 16272-4:2016 (E)
3.9
test construction
construction on which the added device is placed; for in situ measurements, it is an installed noise
reducing device; for qualification tests, it is a reference wall
Note 1 to entry: See 5.2.
3.10
reference plane of the test construction
vertical plane passing through the midpoint of the top edge of the construction (reference wall or
installed noise reducing device) on which the added device has to be placed
Note 1 to entry: See Figures 1, 2, 4, 5, 8.
3.11
reference height of the test construction without the added device, h
ref,0
height of the highest point of the test construction in relation to the surrounding ground surface. This
highest point is not necessarily lying in the plane of longitudinal symmetry of the reference test
construction, if this symmetry exists
Note 1 to entry: See Figure 1.
3.12
reference height of the test construction with the added device on the top, h
ref,ad
height of the highest point of the added device installed on the test construction in relation to the
surrounding ground surface; this highest point is not necessarily lying in the plane of longitudinal
symmetry of the reference test construction, if this symmetry exists
Note 1 to entry: See Figure 4.
3.13
free-field measurement for sound diffraction index measurements
measurement carried out by placing the loudspeaker and the microphone as specified in 5.3, 5.4 and 5.5
without any obstacle, including the test construction with or without added device, between them
Note 1 to entry: See Figure 7.
3.14
Adrienne temporal window
composite temporal window described in 5.8.5
3.15
background noise
noise coming from sources other than the source emitting the test signal
3.16
signal-to-noise ratio, S/N
difference in decibels between the level of the test signal and the level of the background noise at the
moment of detection of the useful event (within the Adrienne temporal window)
3.17
impulse response
time signal at the output of a system when a Dirac function is applied to the input
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Note 1 to entry: The Dirac function, also called δ function, is the mathematical idealization of a signal infinitely
short in time that carries a unit amount of energy.
4 Symbols and abbreviations
For the purposes of this document, the following symbols and abbreviations apply.
Table 1 —Symbols and abbreviations
Symbol or
Designation Unit
abbreviation
α Sound absorption coefficient measured according to EN ISO 354 -
DI Sound diffraction index in the j-th one-third octave frequency band dB
j
DI Sound diffraction index for the reflective reference wall without the added device dB
0,refl
DI Sound diffraction index for the reflective reference wall with the added device dB
ad,refl
DI Sound diffraction index for the absorptive reference wall without the added device dB
0,abs
DI Sound diffraction index for the absorptive reference wall with the added device dB
ad,abs
DI Sound diffraction index for the in situ test construction without the added device dB
0,situ
DI Sound diffraction index for the in situ test construction with the added device dB
ad,situ
ΔDI Sound diffraction index difference for the test sample on the reflective reference wall dB
refl
ΔDI Sound diffraction index difference for the test sample on the absorbing reference wall dB
abs
ΔDI Sound diffraction index difference for the test sample on an situ test construction dB
situ
DL Single-number rating of sound diffraction index difference for the test sample on the dB
ΔDI,refl
reflective reference wall
DL Single-number rating of sound diffraction index difference for the test sample on the dB
ΔDI,abs
absorbing reference wall
DL Single-number rating of sound diffraction index difference for the test sample on the in dB
ΔDI,situ
situ test construction
δ Any input quantity to allow for uncertainty estimates -
i
Δf Width of the j-th one-third octave frequency band Hz
j
f Frequency Hz
F Symbol of the Fourier transform -
f Low frequency limit of sound diffraction index measurements Hz
min
f Sample rate Hz
s
fco Cut-off frequency of the anti-aliasing filter Hz
h Noise barrier height m
B
h Reference height of the test construction m
ref
h Reference height of the test construction without the added device m
ref,0
h Reference height of the test construction with the added device m
ref,ad
h (t) Incident reference component of the free-field impulse response dB
i
h (t) Diffracted component of the impulse response at the k-th measurement point dB
d,k
j Index of the j-th one-third octave frequency band (between 100 Hz and 5 kHz) -
9

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Symbol or
Designation Unit
abbreviation
k Coverage factor -
k Constant used for the anti-aliasing filter -
f
L Minimum length of the reference wall m
b
L Minimum length of the added device under test m
d
M Position of the k-th microphone -
k
n Number of measurement points -
SI Sound Insulation Index measured according to EN 16272-6 dB
t Time s or ms
TW,BH Total length of the Blackman-Harris temporal window ms
T Total length of the Adrienne temporal window ms
W,ADR
u Standard uncertainty -
U Expanded uncertainty -
w (t) Time window (Adrienne temporal window) for the component of the free-field -
ik
impulse response received at the k-th measurement point
w (t) Time window (Adrienne temporal window) for the component of the impulse -
t,k
response diffracted by the top edge of the test construction and received at the k-th
measurement point
5 Sound diffraction index difference measurements
5.1 General principle
The sound source emits a transient sound wave that travels toward the noise reducing device under
test and is partly reflected, partly transmitted and partly diffracted. The microphone placed on the
other side of the noise reducing device receives both the transmitted sound pressure wave travelling
from the sound source through the noise reducing device and the sound pressure wave diffracted by the
top edge of the noise reducing device under test (for the test to be meaningful the diffraction from the
vertical edges of the test construction shall be sufficiently delayed in order to be outside the Adrienne
temporal window). If the measurement is repeated without the added device and the test construction
between the loudspeaker and the microphone, the direct free-field wave can be acquired. The power
spectra of the direct and the top-edge diffracted components, corrected to take into account the path
length difference of the two components, give the basis for calculating the diffraction index.
The final sound diffraction index shall be a weighted average of the diffraction indices measured at
different points (see Figures 1 to 6).
When the test method is applied in situ, the measurement procedure and sound diffraction index
calculation shall be carried out twice, with and without the added device placed on the test
construction.
When the test method is applied on samples purposely built to be tested according to the present
standard, the added device shall be sub
...

SLOVENSKI STANDARD
oSIST prEN 16272-4:2014
01-julij-2014
äHOH]QLãNHQDSUDYH=JRUQMLXVWURMSURJH3URWLKUXSQHRYLUHLQSULSDGDMRþH
QDSUDYHNLYSOLYDMRQDãLUMHQMH]YRNDY]UDNX3UHVNXVQDPHWRGD]DXJRWDYOMDQMH
DNXVWLþQLKODVWQRVWLGHO6SHFLILþQHNDUDNWHULVWLNH7HUHQVNHYUHGQRVWL
GLIUDNFLMH]YRNDSULXVPHUMHQHP]YRþQHPSROMX
Railway applications - Track - Noise barriers and related devices acting on airborne
sound propagation - Test method for determining the acoustic performance - Part 4:
Intrinsic characteristics - In situ values of sound diffraction under direct sound field
conditions
Bahnanwendungen - Oberbau - Lärmschutzwände und verwandte Vorrichtungen zur
Beeinflussung der Luftschallausbreitung - Prüfverfahren zur Bestimmung der
akustischen Eigenschaften - Teil 4: Produktspezifische Merkmale - In-situ-Werte von
Schallbeugung in direkten Schallfeldern
Applications ferroviaires - Voie - Dispositifs de réduction du bruit - Méthode d'essai pour
la détermination des performances acoustiques - Partie 4: Caractéristiques intrinsèques -
Valeurs in situ de la diffraction acoustique dans des conditions de champ acoustique
direct
Ta slovenski standard je istoveten z: prEN 16272-4
ICS:
17.140.30 Emisija hrupa transportnih Noise emitted by means of
sredstev transport
93.100 Gradnja železnic Construction of railways
oSIST prEN 16272-4:2014 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 16272-4:2014

EUROPEAN STANDARD
DRAFT
prEN 16272-4
NORME EUROPÉENNE

EUROPÄISCHE NORM

May 2014
ICS 93.100
English Version
Railway applications - Track - Noise barriers and related devices
acting on airborne sound propagation - Test method for
determining the acoustic performance - Part 4: Intrinsic
characteristics - In situ values of sound diffraction under direct
sound field conditions
Applications ferroviaires - Voie - Dispositifs de réduction du Bahnanwendungen - Oberbau - Lärmschutzwände und
bruit - Méthode d'essai pour la détermination des verwandte Vorrichtungen zur Beeinflussung der
performances acoustiques - Partie 4: Caractéristiques Luftschallausbreitung - Prüfverfahren zur Bestimmung der
intrinsèques - Valeurs in situ de la diffraction acoustique akustischen Eigenschaften - Teil 4: Produktspezifische
dans des conditions de champ acoustique direct Merkmale - In-situ-Werte von Schallbeugung in direkten
Schallfeldern
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 256.

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.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey 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: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 16272-4:2014 E
worldwide for CEN national Members.

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Contents
Foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Symbols and abbreviations . 7
5 Sound diffraction index difference measurements . 9
5.1 General principle. 9
5.2 Dimensions and specifications . 9
5.3 Positions of the sound source . 10
5.4 Position of the microphone(s) . 11
5.5 Free-field measurements . 11
5.6 Measured quantity . 16
5.7 Measuring equipment . 16
5.8 Data processing . 18
5.9 Positioning of the measuring equipment . 22
5.10 Sound diffraction index difference . 23
5.11 Sample surface and meteorological conditions . 23
6 Measurement uncertainty . 24
7 Measuring procedure . 24
8 Test report . 25
8.1 Expression of results . 25
8.2 Further information. 25
Annex A (informative) Indoor measurements for product qualification . 26
A.1 Parasitic reflections . 26
A.2 Reverberation time of the room . 26
Annex B (informative) Measurement uncertainty . 27
B.1 General . 27
B.2 Expression for the calculation of sound insulation index . 27
B.3 Contributions to measurement uncertainty . 28
B.4 Expanded uncertainty of measurement . 28
B.5 Measurement uncertainty based upon reproducibility data . 29
Bibliography . 30

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Foreword
This document (prEN 16272-4:2014) has been prepared by Technical Committee CEN/TC 256 “Railway
applications”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This European Standard has been prepared, under the direction of Technical Committee CEN/TC 256 “Railway
applications”, by Working Group 40 “Noise barriers”.
This European Standard is one of the series EN 16272 “Railway applications – Track – Noise barriers and related
devices acting on airborne sound propagation – Test method for determining the acoustic performance” as listed
below:
— Part 1: Intrinsic characteristics – Sound absorption in the laboratory under diffuse sound field conditions
— Part 2: Intrinsic characteristics – Airborne sound insulation in the laboratory under diffuse sound field
conditions
— Part 3-1: Normalized railway noise spectrum and single number ratings for diffuse field applications
— Part 3-2: Normalized railway noise spectrum and single number ratings for direct field applications
— Part 4: Intrinsic characteristics – In situ values of sound diffraction under direct sound field conditions
— Part 5: Intrinsic characteristics – In situ values of sound reflection under direct sound field conditions
— Part 6: Intrinsic characteristics – In situ values of airborne sound insulation under direct sound field conditions
— Part 7: Extrinsic characteristics – In situ values of insertion loss
It should be read in conjunction with:
EN 16272-3-2, Railway applications – Track – Noise barriers and related devices acting on airborne sound
propagation – Test method for determining the acoustic performance – Part 3-2: Normalized railway noise
spectrum and single number ratings for direct field applications
EN 16272-6, Railway applications – Track – Noise barriers and related devices acting on airborne sound
propagation – Test method for determining the acoustic performance – Part 6: Intrinsic characteristics – In situ
values of airborne sound insulation under direct sound field conditions
3

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Introduction
Part of the market of railway noise barriers and related devices acting on airborne sound propagation is constituted
of products to be added on the top of noise barriers and intended to contribute to sound attenuation acting primarily
on the diffracted sound field. These products will be called added devices. This standard has been developed to
specify a test method for determining the acoustic performance of added devices.
The test method can be applied in situ, i.e. where the railway noise barriers and the added devices are installed.
The method can be applied without damaging the railway noise barriers or the added devices.
The method can be used to qualify products before the installation along railways as well as to verify the
compliance of installed added devices to design specifications. Repeated application of the method can be used to
verify the long term performance of added devices.
NOTE This method could be used to qualify added devices for other applications, e.g. to be installed along roads or nearby
industrial sites. In this case special care has to be taken into account in considering the location of the noise sources and the
single-number ratings should be calculated using an appropriate spectrum.
No other national or international standard exists about the subject of this standard.
4

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1 Scope
This European Standard describes a test method for determining the intrinsic characteristics of sound diffraction of
added devices installed on the top of railway noise barriers. The test method prescribes measurements of the
sound pressure level at several reference points near the top edge of a noise barrier with and without the added
device installed on its top. The effectiveness of the added device is calculated as the difference between the
measured values with and without the added devices, correcting for any change in height (the method described
gives the acoustic benefit over a simple barrier of the same height; however, in practice the added device can raise
the height and this would provide additional screening depending on the source and receiver positions).
The test method is intended for the following applications:
— preliminary qualification, outdoors or indoors, of added devices to be installed on noise barriers;
— determination of sound diffraction index difference of added devices in actual use;
— comparison of design specifications with actual performance data after the completion of the construction
work;
— verification of the long term performance of added devices (with a repeated application of the method);
— interactive design process of new products, including the formulation of installation manuals.
The test method can be applied both in situ and on samples purposely built to be tested using the method
described here.
Results are expressed as a function of frequency, in one-third octave bands between 100 Hz and 5 kHz. If it is not
possible to get valid measurements results over the whole frequency range indicated, the results shall be given in
the restricted frequency range and the reasons of the restriction(s) shall be clearly reported. A single-number rating
is calculated from frequency data.
For indoors measurements see Annex A.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for
its application. For dated references, only the edition cited applies. For undated references, the latest edition of the
referenced document (including any amendments) applies.
EN 16272-3-2, Railway applications – Track – Noise barriers and related devices acting on airborne sound
propagation – Test method for determining the acoustic performance – Part 3-2: Normalized railway noise
spectrum and single number ratings for direct field applications
EN 16272-6, Railway applications – Track – Noise barriers and related devices acting on airborne sound
propagation – Test method for determining the acoustic performance – Part 6: Intrinsic characteristics – In situ
values of airborne sound insulation under direct sound field conditions
EN ISO 354, Acoustics – Measurement of sound absorption in a reverberation room
IEC 60942, Electroacoustics – Sound calibrators
IEC 61260, Electroacoustics – Octave-band and fractional-octave-band filters
IEC 61672-1, Electroacoustics – Sound level meters – Part 1: Specifications
ISO/IEC Guide 98, Guide to the expression of uncertainty in measurement
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3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
noise barrier
noise reducing device, which obstructs the direct transmission of airborne sound emanating from railways; it may
either span or overhang the railway
Note 1 to entry Noise barriers are generally made of acoustic and structural elements (3.3 and 3.4).
3.2
cladding
noise reducing device, which is attached to a wall or other structure and reduces the amount of sound reflected
Note 1 to entry Claddings are generally made of acoustic and structural elements (3.3 and 3.4).
3.3
acoustic element
element whose primary function is to provide the acoustic performance of the device
3.4
structural element
element whose primary function is to support or hold in place acoustic elements
3.5
added device
added component that influences the acoustic performance of the original noise-reducing device (acting primarily
on the diffracted energy)
Note 1 to entry In some noise barriers the acoustic function and the structural function cannot be clearly separated and
attributed to different components
3.6
rail side exposure
the use of the product as a noise reducing device installed alongside railways
3.7
sound diffraction index
the result of a sound diffraction test whose components are described by the formula in 5.6. DI refers to
x,refl
measurements on a reflective reference wall. DI refers to measurements on an absorptive reference wall. DI
x,abs x,situ
refers to in situ measurements; where x is “0” when the added device is not on the top of the test construction and
“ad” when the added device is on the top of the test construction (see 3.2)
3.8
sound diffraction index difference
difference between the results of sound diffraction tests on the same reference wall with and without an added
device on the top, described by the formulae in 5.10
3.9
test construction
construction on which the added device is placed. For in situ measurements it is an installed noise reducing device;
for qualification tests it is a reference wall (see 5.2)
3.10
reference plane of the test construction
the vertical plane passing through the midpoint of the top edge of the construction (reference wall or installed noise
reducing device) on which the added device has to be placed (see Figures 1, 2, 4, 5, 8)
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3.11
reference height of the test construction without the added device, h
ref,0
height of the highest point of the test construction in relation to the surrounding ground surface. This highest point
is not necessarily lying in the plane of longitudinal symmetry of the reference test construction, if this symmetry
exists (Figure 1)
3.12
reference height of the test construction with the added device on the top, h
ref,add
height of the highest point of the added device installed on the test construction in relation to the surrounding
ground surface. This highest point is not necessarily lying in the plane of longitudinal symmetry of the reference test
construction, if this symmetry exists (Figure 4)
3.13
free-field measurement for sound diffraction index measurements
Measurement carried out placing the loudspeaker and the microphone as specified in 5.3, 5.4 and 5.5 without any
obstacle, including the test construction with or without added device, between them (see for example Figure 7)
3.14
Adrienne temporal window
the composite temporal window described in 5.8.5
3.15
background noise
noise coming from sources other than the source emitting the test signal
3.16
signal-to-noise ratio, S/N
The difference in decibels between the level of the test signal and the level of the background noise at the moment
of detection of the useful event (within the Adrienne temporal window)
3.17
impulse response
the time signal at the output of a system when a Dirac function is applied to the input. The Dirac function, also
called δ function, is the mathematical idealization of a signal infinitely short in time that carries a unit amount of
energy
4 Symbols and abbreviations
For the purposes of this document, the following symbols and abbreviations apply.
Table 1 —Symbols and abbreviations
Symbol or
Designation Unit
abbreviation
α Sound absorption coefficient measured according to EN ISO 354 -
DI Sound diffraction index in the j-th one-third octave frequency band dB
j
DI Sound diffraction index for the reflective reference wall without the added device dB
0,refl
DI Sound diffraction index for the reflective reference wall with the added device dB
ad,refl
DI Sound diffraction index for the absorptive reference wall without the added device dB
0,abs
DI Sound diffraction index for the absorptive reference wall with the added device dB
ad,abs
DI Sound diffraction index for the in situ test construction without the added device dB
0,situ
DI Sound diffraction index for the in situ test construction with the added device dB
ad,situ
ΔDI Sound diffraction index difference for the test sample on the reflective reference dB
refl
wall
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Symbol or
Designation Unit
abbreviation
ΔDI Sound diffraction index difference for the test sample on the absorbing reference dB
abs
wall
ΔDI Sound diffraction index difference for the test sample on an situ test construction dB
situ
DL Single-number rating of sound diffraction index difference for the test sample on the dB
ΔDI,refl
reflective reference wall
DL Single-number rating of sound diffraction index difference for the test sample on the dB
ΔDI,abs
absorbing reference wall
DL Single-number rating of sound diffraction index difference for the test sample on the dB
ΔDI,situ
in situ test construction
δ Any input quantity to allow for uncertainty estimates -
i
Δf Width of the j-th one-third octave frequency band Hz
i
f Frequency Hz
F Symbol of the Fourier transform -
f Low frequency limit of sound diffraction index measurements Hz
min
f Sample rate Hz
s
f Cut-off frequency of the anti-aliasing filter Hz
co
h Noise barrier height m
B
h Reference height of the test construction m
ref
h Reference height of the test construction without the added device m
ref,0
h Reference height of the test construction with the added device m
ref,ad
h(t) Incident reference component of the free-field impulse response dB
i
h (t) Diffracted component of the impulse response at the k-th measurement point dB
d,k
j Index of the j-th one-third octave frequency band (between 100 Hz and 5 kHz) -
k Coverage factor -
k Constant used for the anti-aliasing filter -
f
L Minimum length of the reference wall m
b
L Minimum length of the added device under test m
d
n Number of measurement points -
SI Sound Insulation Index measured according to EN 16272–6 dB
t Time s or
ms
T Length of the Blackman-Harris trailing edge of the Adrienne temporal window ms
W,BH
T Total length of the Adrienne temporal window ms
W,ADR
u Standard uncertainty -
U Expanded uncertainty -
w (t) Time window (Adrienne temporal window) for the component of the free-field -
ik
impulse response received at the k-th measurement point
w (t) Time window (Adrienne temporal window) for the component of the impulse -
t,k
response diffracted by the top edge of the test construction and received at the k-th
measurement point
8

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5 Sound diffraction index difference measurements
5.1 General principle
The sound source emits a transient sound wave that travels toward the noise reducing device under test and is
partly reflected, partly transmitted and partly diffracted by it. The microphone placed on the other side of the noise
reducing device receives both the transmitted sound pressure wave travelling from the sound source through the
noise reducing device and the sound pressure wave diffracted by the top edge of the noise reducing device under
test (for the test to be meaningful the diffraction from the vertical edges of the test construction shall be sufficiently
delayed in order to be outside the Adrienne temporal window). If the measurement is repeated without the added
device and the test construction between the loudspeaker and the microphone, the direct free-field wave can be
acquired. The power spectra of the direct and the top-edge diffracted components, corrected to take into account
the path length difference of the two components, give the basis for calculating the diffraction index.
The final sound diffraction index shall be a weighted average of the diffraction indices measured at different points
(see Figures 1 to 6).
When the test method is applied in situ, the measurement procedure and sound diffraction index calculation shall
be carried out two times, with and without the added device placed on the test construction.
When the test method is applied on samples purposely built to be tested according to the present standard, the
added device shall be subsequently placed on the top of two reference walls (reflective and absorptive), or of the
same reference wall in two different configurations, (see 5.2) and the measurement procedure and sound
diffraction index calculation shall be carried out for both walls, with and without the added device on the top.
The measurement must take place in an essentially free field in the direct surroundings of the device, i.e. a field
free from reflections coming from surfaces other than the surface of the device under test. For this reason, the
acquisition of an impulse response having peaks as sharp as possible is recommended: in this way, the reflections
coming from other surfaces than the tested device can be identified from their delay time and rejected.
5.2 Dimensions and specifications
5.2.1 Added devices
The added device shall have a minimum length L of 10 m. The reference wall shall have a minimum length L of
d b
10 m and a minimum height of 4 m. The reference wall shall be vertical, flat and fixed firmly and without any air
gaps on a supporting construction (foundation, floor, etc.). The top surface of the supporting construction shall be
level with the surrounding ground surface.
The maximum size of the added device measured perpendicularly from the reference plane either in the direction of
the source or in the direction of the microphones shall not exceed a value of 1,0 m (see Figure 8).
5.2.2 Reference walls
Two versions of the reference wall shall be used in the tests:
A A reflective reference wall, constructed of homogeneous panels with a smooth surface finish. The wall shall be
free of air leaks and shall have a thickness not greater than 0,20 m. The wall shall have the minimum values of
Sound Insulation Index measured according to EN 16272–6 specified in Table 2, in order that the sound
transmission through the reference wall is negligible.
Table 2 —Minimum values of the Sound Insulation Index of the reference wall, measured according to
EN 16272–6 (tolerance: ± 0,5 dB)
Octave centre frequency (Hz) 125 250 500 1000 2000 4000
SI (dB) 21,0 22,0 24,0 26,0 29,0 32,0

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B An absorptive reference wall, constructed as mentioned under A, lined on the source side with an absorptive
flat layer of a single porous material having the minimum values of sound absorption coefficient measured
according to EN ISO 354 specified in Table 3.
Table 3 —Minimum values of the sound absorption coefficient for the absorptive treatment of the reference
wall, measured according to EN ISO 354 (tolerance: ± 0,05)
Octave centre frequency (Hz) 125 250 500 1000 2000 4000
α 0,20 0,50 0,85 0,95 0,95 0,95
5.2.3 In situ tests
When applying the test method in situ on existing noise barriers, with the intention of obtaining results valid over the
entire frequency range specified in 5.6, the test construction shall satisfy the requirements in 5.2.2.
If these requirements cannot be fulfilled by the existing noise barrier, the obtained results shall only be valid over a
restricted frequency range (see 5.8.7) and for the type of noise reducing device being tested.
5.3 Positions of the sound source
Two angles of incidence, 90° and 45°, shall be used (see Figures 2 and 5).
For execution of the diffraction test at a right angle to the test construction the sound source shall be placed as
follows (see Figures 1, 2, 4 and 5):
— in the vertical plane containing the perpendicular bisector plane to the reference plane;
— horizontally: at 2 m distance from the reference plane of the test construction;
— vertically: in relation to the reference height h of the test construction,
ref
— for the obligatory source position S1: centre of the source 0,50 m lower than h ;
ref
— for the obligatory source position S2: centre of the source 0,15 m lower than h ;
ref
— oriented towards the microphone position M1 (see 5.4, and Figures 1 and 3).
For execution of the diffraction test at an angle of 45° with the reference plane of t
...