SIST EN 16272-3-2:2023+A1:2026

• Abstract:

  This document specifies a normalized railway noise spectrum for the evaluation and assessment of the acoustic performance of devices designed to reduce airborne railway noise near railways.; All noise reducing devices different from noise barriers and related devices acting on airborne sound propagation, e.g. devices for attenuation of ground borne vibration and on board devices are outside of the scope of this document.

• Status: Published
• Publication Date: 27-May-2026
• 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: 27-May-2026
• Due Date: 01-Aug-2026
• Completion Date: 28-May-2026
• Directive: 2022-01-0641 - Pravilnik o spodnjem ustroju železniških prog
• Ref Project: EN 16272-3-2:2023+A1:2026 - Railway applications - Infrastructure - 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 sound field applications

• Replaces: SIST EN 16272-3-2:2023 - Railway applications - Infrastructure - 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
• Effective Date: 01-Jul-2026
• Referred By: SIST EN 16272-5:2024 - Railway applications - Infrastructure - Noise barriers and related devices acting on airborne sound propagation - Test method for determining the acoustic performance - Part 5: Intrinsic characteristics - Sound absorption under direct sound field conditions
• Effective Date: 25-Mar-2026
• Referred By: SIST EN 16272-6:2024 - Railway applications - Infrastructure - Noise barriers and related devices acting on airborne sound propagation - Test method for determining the acoustic performance - Part 6: Intrinsic characteristics - Airborne sound insulation under direct sound field conditions
• Effective Date: 25-Mar-2026
• Referred By: 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
• Effective Date: 25-Mar-2026
• Referred By: SIST EN 16272-6:2015 - 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
• Effective Date: 25-Mar-2026

SIST EN 16272-3-2:2023+A1:2026 is a CEN European Standard for railway applications. It specifies a normalized railway noise spectrum and the single-number ratings used to assess sound reflection, airborne sound insulation and diffraction index difference for noise barriers and related devices acting on airborne sound propagation in direct sound field applications near railways.

Engineers, test laboratories, manufacturers and infrastructure buyers use SIST EN 16272-3-2:2023+A1:2026 to turn frequency-dependent acoustic measurements into comparable one-number results. The document is meant to be read with the linked measurement parts of the EN 16272 series.

What does SIST EN 16272-3-2:2023+A1:2026 specify?

SIST EN 16272-3-2:2023+A1:2026 specifies the normalized railway noise spectrum used to evaluate the acoustic performance of devices that reduce airborne railway noise near railways. It applies to noise barriers and related devices acting on airborne sound propagation in direct sound field conditions.

The scope excludes other noise-reducing devices such as products for ground-borne vibration attenuation and on-board devices. In practice, that means the document is for barrier-type and related trackside products, not for rolling stock equipment or vibration control systems.

The document is organized into:

• Clause 1 Scope
• Clause 2 Normative references
• Clause 3 Terms, definitions, symbols and abbreviated terms
• Clause 4 Normalized railway noise spectrum for direct sound field applications
• Clause 5 Single-number rating of sound reflection index DL
• Clause 6 Single-number rating of sound insulation index DL
• Clause 7 Single-number ratings of diffraction index difference DL
• Clause 8 Uncertainty of single-number ratings
• Clause 9 Expression of results
• Annexes A to D, all informative

Annex	What it covers
Annex A	Guidance on using the single-number rating of sound reflection index DL
Annex B	Guidance on using the single-number rating of sound insulation index DL
Annex C	Guidance on using the single-number rating of diffraction index difference DL
Annex D	Measurement uncertainty of the single-number ratings

What are the key requirements of SIST EN 16272-3-2:2023+A1:2026?

SIST EN 16272-3-2:2023+A1:2026 sets one reference railway noise spectrum and then uses it to weight frequency-band measurement results into single-number ratings. That is the core idea: take band-by-band acoustic data from the related test parts, apply the same railway spectrum, and report a single result that can be compared between products.

Reference spectrum

Clause 4 requires use of the normalized railway noise spectrum in Table 2 for direct sound field applications near railways. The spectrum covers one-third octave bands from 100 Hz to 5 kHz.

In practice, this spectrum is the reference weighting for every rating in the document. It makes different products comparable under the same assumed railway-noise conditions.

Sound reflection rating

Clause 5 defines the single-number rating of sound reflection index DL from the frequency-dependent reflection index values measured according to EN 16272-5. The rating is calculated by weighting each band with the normalized railway noise spectrum.

For qualification work, the rating is calculated for samples of minimum dimensions conforming to EN 16272-5. For other uses, the document says the result shall be reported with the frequency range used for the calculation. The rating is rounded to one decimal digit, and the calculation limits the ratio in the formula to 0.99 when needed.

Sound insulation ratings

Clause 6 defines single-number ratings for sound insulation index in three forms: one for acoustic elements, one for posts, and one global rating. The frequency-band values come from EN 16272-6 and are weighted with the same normalized railway noise spectrum.

For acoustic elements and posts, the document requires minimum sample dimensions conforming to EN 16272-6. If a post rating cannot be derived, the global rating is equal to the acoustic-element rating. The reported values are rounded to one decimal digit and should be accompanied by the relevant frequency range when used outside qualification.

Diffraction index difference ratings

Clause 7 covers added devices mounted on a reflective reference wall, an absorptive reference wall, or an in situ test construction. The frequency-band diffraction index difference values are weighted with the normalized railway noise spectrum to produce single-number ratings.

For these ratings, the samples must conform to the minimum dimensions of EN 16272-4:2016. The document also requires reporting to one decimal digit and gives separate formulas for the three mounting conditions.

Uncertainty and reporting

Clause 8 allows reproducibility data to be used as an estimate of combined standard uncertainty when no analytical uncertainty budget is available. Clause 9 then ties the rating to the relevant test report from EN 16272-4, EN 16272-5 or EN 16272-6.

In practice, this means the final report should not just give a number. For reflection and insulation ratings, it should also state the expanded uncertainty. For diffraction index difference ratings, the document requires the rounded single-number result in the test report.

What terms does SIST EN 16272-3-2:2023+A1:2026 define?

SIST EN 16272-3-2:2023+A1:2026 defines a small set of terms and symbols that drive the calculations.

• normalized railway noise spectrum - the reference spectrum used to calculate acoustic performance near railways in terms of single-number ratings.
• one-third octave bands level - the relative A-weighted sound pressure level used for one band of the normalized railway noise spectrum.
• RI - the sound reflection index in a one-third octave band, which feeds the reflection rating.
• SI - the sound insulation index in a one-third octave band, which feeds the insulation ratings.
• ΔDI,refl - the diffraction index difference for an added device mounted on a reflective reference wall.
• ΔDI,abs - the diffraction index difference for an added device mounted on an absorptive reference wall.
• ΔDI,situ - the diffraction index difference for an added device mounted on an in situ test construction.
• m - the lowest reliable one-third octave frequency band used in a calculation.

Who uses SIST EN 16272-3-2:2023+A1:2026?

SIST EN 16272-3-2:2023+A1:2026 is used by people who test, specify, compare or buy railway noise barriers and related devices. Typical users include acoustic test laboratories, manufacturers, consultants, railway infrastructure managers, quality teams and procurement teams.

They use it to convert banded acoustic measurements into single-number ratings, compare products on the same railway-noise basis, and state results in test reports with the required frequency range and uncertainty information.

What changed in SIST EN 16272-3-2:2023+A1:2026 from the previous edition?

SIST EN 16272-3-2:2023+A1:2026 supersedes EN 16272-3-2:2023 and includes Amendment 1 approved by CEN on 20 April 2026. The foreword lists these main changes:

• the terms, definitions, symbols and abbreviations clause was updated
• an annex on reproducibility and repeatability values was added so measurement uncertainty and the related confidence level can be declared
• the bibliography chapter was added
• Formula (4) for DL was changed
• all single-number ratings are reported after rounding to the first decimal digit

Which standards are used with SIST EN 16272-3-2:2023+A1:2026?

SIST EN 16272-3-2:2023+A1:2026 depends on three normative references:

• EN 16272-4:2016 - provides the measurement basis for diffraction index difference
• EN 16272-5 - provides the sound reflection index measurement and the direct sound field basis used for DL
• EN 16272-6 - provides the airborne sound insulation measurement and the direct sound field basis used for DL

The foreword also places the document in the EN 16272 series, alongside parts 1, 2, 3-1, 4, 5, 6 and CEN/TS 16272-7. Together, those parts cover diffuse sound field, direct sound field, intrinsic characteristics and in situ insertion loss for noise barriers and related devices.

What does the SIST EN 16272-3-2:2023+A1:2026 document contain?

The document contains the normalized railway noise spectrum used in the calculations, the symbol and abbreviation table, the equations for DL and the diffraction index difference ratings, and the rules for reporting the results. It also contains guidance annexes that explain how to use the reflection, insulation and diffraction ratings in practice.

Annex D discusses measurement uncertainty and how reproducibility data can be used when a full uncertainty budget is not available. The bibliography includes an interlaboratory study on repeatability and reproducibility and ISO/IEC Guide 98-3 for uncertainty of measurement.

SLOVENSKI STANDARD
01-julij-2026
Nadomešča:
SIST EN 16272-3-2:2023
Železniške naprave - Infrastruktura - Protihrupne ovire in pripadajoče naprave, ki
vplivajo na širjenje zvoka v zraku - Preskusna metoda za ugotavljanje akustičnih
lastnosti - 3-2. del: Normalizirani spekter železniškega hrupa in enomestne
številske stopnje usmerjenega zvočnega polja (vključno z dopolnilom A1)
Railway applications - Infrastructure - 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 sound
field applications
Bahnanwendungen - Oberbau - Lärmschutzwände und verwandte Vorrichtungen zur
Beeinflussung der Luftschallausbreitung - Prüfverfahren zur Bestimmung der
akustischen Eigenschaften - Teil 3‑2: Standardisiertes Schienenverkehrslärmspektrum
und Einzahl-Angaben für gerichtete Schallfelder
Applications ferroviaires - Infrastructure - Dispositifs de réduction du bruit - Méthode
d'essai pour la détermination de la performance acoustique - Partie 3-2 : Spectre de bruit
ferroviaire normalisé et indices uniques d'évaluation pour des applications en champ
sonore direct
Ta slovenski standard je istoveten z: EN 16272-3-2:2023+A1:2026
ICS:
17.140.30 Emisija hrupa transportnih Noise emitted by means of
sredstev transport
93.100 Gradnja železnic Construction of railways
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 16272-3-2:2023+A1
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2026
EUROPÄISCHE NORM
ICS 93.100 Supersedes EN 16272-3-2:2023
English Version
Railway applications - Infrastructure - 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 sound field applications
Applications ferroviaires - Infrastructure - Dispositifs Bahnanwendungen - Oberbau - Lärmschutzwände und
de réduction du bruit - Méthode d'essai pour la verwandte Vorrichtungen zur Beeinflussung der
détermination de la performance acoustique - Partie 3- Luftschallausbreitung - Prüfverfahren zur Bestimmung
2 : Spectre de bruit ferroviaire normalisé et indices der akustischen Eigenschaften - Teil 3-2:
uniques d'évaluation pour des applications en champ Standardisiertes Schienenverkehrslärmspektrum und
sonore direct Einzahl-Angaben für gerichtete Schallfelder
This European Standard was approved by CEN on 4 September 2023 and includes Amendment 1 approved by CEN on 20 April
2026.
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, 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.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATIO N

EUROPÄISCHES KOMITEE FÜR NORMUN G

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 16272-3-2:2023+A1:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions, symbols and abbreviated terms . 6
3.1 Terms and definitions . 6
3.2 Symbols and abbreviated terms . 7
4 Normalized railway noise spectrum for direct sound field applications . 8
5 Single-number rating of sound reflection index DL . 8
RI
6 Single-number rating of sound insulation index DL . 9
SI
6.1 General. 9
6.2 Acoustic elements . 9
6.3 Posts . 10
6.4 Global . 10
7 Single-number ratings of diffraction index difference DL . 11
ΔDI
7.1 General. 11
7.2 Single-number rating of diffraction index difference DL . 11
ΔDI,refl
7.3 Single-number rating of diffraction index difference DL . 12
ΔDI,abs
7.4 Single-number rating of diffraction index difference DL . 12
ΔDI,situ
8 Uncertainty of single-number ratings . 12
9 Expression of results . 12
Annex A (informative) Guidance note on use of the single-number rating of sound reflection
index DL . 14
RI
Annex B (informative) Guidance note on use of the single-number rating of sound insulation
index DL . 15
SI
Annex C (informative) Guidance note on use of the single-number rating of diffraction index
difference DL . 16
ΔDI
Annex D (informative) Measurement uncertainty of the single-number ratings . 17
D.1 General. 17
D.2 Measurement uncertainty based upon reproducibility data for DL . 17
RI
D.3 Measurement uncertainty based upon reproducibility data for DL . 17
SI
D.4 Measurement uncertainty based upon reproducibility data for DL . 18
ΔDI
Bibliography . 20
European foreword
This document (EN 16272-3-2:2023+A1:2026) has been prepared by Technical Committee CEN/TC 256
“Railway application”, 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 November 2026, and conflicting national standards shall
be withdrawn at the latest by November 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document includes Amendment 1 approved by CEN on 20 April 2026.
The start and finish of text introduced or altered by amendment is indicated in the text by tags !".
This document supersedes !EN 16272-3-2:2023".
The main changes compared to the previous edition are listed below:
— The ‘Terms, definitions, symbols and abbreviations’ clause has been updated;
— An annex with the values of the standard deviation of reproducibility and repeatability of single-
number ratings has been added; this makes possible the declaration of the measurement uncertainty
and the related confidence level, which is now mandatory (Annex C);
— The Bibliography chapter has been added.
!—  Formula (4) for DL has been changed.
SI,G
—  All single-number ratings are reported after having been rounded to the first decimal digit."
EN 16272-3-2 is part of a series and is intended to be read in conjunction with the other parts. All parts
are listed in the following:
— EN 16272-1, Railway applications – Infrastructure — Noise barriers and related devices acting on
airborne sound propagation — Test method for determining the acoustic performance — Part 1:
Intrinsic characteristics — Sound absorption under diffuse sound field conditions
— EN 16272-2, Railway applications – Infrastructure — Noise barriers and related devices acting on
airborne sound propagation — Test method for determining the acoustic performance — Part 2:
Intrinsic characteristics — Airborne sound insulation under diffuse sound field conditions
— EN 16272-3-1, Railway applications – Infrastructure — Noise barriers and related devices acting on
airborne sound propagation — Test method for determining the acoustic performance — Part 3-1:
Normalized railway noise spectrum and single number ratings for diffuse sound field applications
— EN 16272-3-2, Railway applications – Infrastructure — 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 sound field applications (the
present document)
— EN 16272-4, 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
— EN 16272-5, Railway applications – Infrastructure — Noise barriers and related devices acting on
airborne sound propagation — Part 5: Intrinsic characteristics —Sound absorption under direct sound
field conditions
— EN 16272-6, Railway applications – Infrastructure — Noise barriers and related devices acting on
airborne sound propagation — Test method for determining the acoustic performance — Part 6:
Intrinsic characteristics — Airborne sound insulation under direct sound field conditions
— CEN/TS 16272-7, Railway applications – Track — Noise barriers and related devices acting on
airborne sound propagation — Test method for determining the acoustic performance — Part 7:
Extrinsic characteristics — In situ values of insertion loss
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, 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 the United
Kingdom.
Introduction
1 2
This document is to be read in conjunction with EN 16272-5 and EN 16272-6 and is applied only to
situations as described in those documents (direct sound field conditions).
As the two main intrinsic acoustic characteristics of noise barriers and related devices acting on airborne
sound propagation in a direct sound field, the sound reflection index and the sound insulation index, are
frequency dependent, there is a need to define a reference railway noise spectrum for test purposes.
Also, the diffraction index difference, the main intrinsic acoustic characteristic of added devices, i.e.
products to be added on the top of noise barriers and intended to contribute to sound attenuation acting
primarily on the diffracted sound field, is frequency dependent and there is an analogous need to define
a reference railway noise spectrum for test purposes.
This document defines the basic properties of railway noise measured at the rail track side in terms of a
characteristic normalized railway noise spectrum, which is needed to evaluate single-number ratings of
noise barriers and related devices acting on airborne sound propagation, except those used in
reverberant conditions, e.g. inside tunnels or deep trenches.

Under preparation. Stage at the time of publication: FprEN 16272-5:2023.
Under preparation. Stage at the time of publication: FprEN 16272-6:2023.
1 Scope
This document specifies a normalized railway noise spectrum for the evaluation and assessment of the
acoustic performance of devices designed to reduce airborne railway noise near railways.
All noise reducing devices different from noise barriers and related devices acting on airborne sound
propagation, e.g. devices for attenuation of ground borne vibration and on board devices are outside of
the scope of this document.
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 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
EN 16272-5 , Railway applications - Infrastructure - Noise barriers and related devices acting on airborne
sound propagation - Test method for determining the acoustic performance - Part 5: Intrinsic characteristics
- Sound absorption under direct sound field conditions
EN 16272-6 , Railway applications - Infrastructure - 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 Terms, definitions, symbols and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
NOTE For the purpose of this document, the following definitions take precedence over other definitions from
the above websites.
3.1.1
normalized railway noise spectrum
spectrum that is used for the calculation of the acoustic performance of noise barriers and related devices
acting on airborne sound propagation near railways, in terms of !single-number ratings of sound
absorption, airborne sound insulation and diffraction index difference"
Note 1 to entry: The spectrum is expressed in terms of relative A-weighted sound pressure levels in decibels, for
one-third octave bands, Li, in the frequency range from 100 Hz to 5 kHz.
3.1.2
one-third octave bands level
L
i
relative A-weighted sound pressure level in decibels, of a normalized railway noise spectrum for one-
third octave band with centre frequency f
i
3.2 Symbols and abbreviated terms
For the purposes of this document, the following symbols apply.
Table 1 — Symbols and abbreviations
Symbol or
Designation Unit
abbreviation
DL Single-number rating of sound reflection index in a direct sound field dB
RI
expressed as a difference of A weighted sound pressure levels
DL Single-number rating of sound insulation index in a direct sound field dB
SI
expressed as a difference of A-weighted sound pressure levels
DL Single-number rating of diffraction index difference of an added device dB
ΔDI,refl
mounted on a reflective reference wall in a direct sound field expressed as
a difference of A-weighted sound pressure levels
DL Single-number rating of diffraction index difference of an added device dB
ΔDI,abs
mounted on an absorptive reference wall in a direct sound field expressed
as a difference of A-weighted sound pressure levels
DL Single-number rating of diffraction index difference of an added device dB
ΔDI,situ
mounted on an in situ test construction in a direct sound field expressed as
a difference of A-weighted sound pressure levels
f Nominal centre frequency of the i-th one-third octave band Hz
i
i Index of the i-th one-third octave frequency band, between 100 Hz and -
5 kHz
L Relative A-weighted sound pressure level, in decibels, of the normalized dB
i
traffic noise spectrum in the i-th one-third octave band
L !Total length of an acoustic element before installation" m
E
m number of the lowest reliable one-third octave frequency band according
-
1 2
to EN 16272-5 (for RI) or EN 16272-6 (for SI)
RI Sound reflection index in the i-th one-third octave band -
i
SI Sound insulation index in the i-th one-third octave band dB
i
Standard deviation of reproducibility of the single-number rating for -
s
R,DL
SI,E
“elements”
Standard deviation of reproducibility of the single-number rating for -
s
R,DL
SI,P
“posts”
Standard deviation of reproducibility of the single-number rating for -

s
R,DL
SI,G
“global”
w Weight for the single-number rating for acoustic elements -
E
w Weight for the single-number rating across posts -
P
ΔDI Sound diffraction index difference of an added device mounted on a dB
refl
reflective reference wall
ΔDIabs Sound diffraction index differenc
...