EN 60268-16:2011

Sound system equipment - Part 16: Objective rating of speech intelligibility by speech transmission index

IEC 60268-16:2011 specifies objective methods for rating the transmission quality of speech with respect to intelligibility. It provides a comprehensive manual for all types of users of the STI method in the fields of audio, communications and acoustics. Three methods are presented, which are closely related and are referred to as STI, STIPA, and STITEL. The first two methods are intended for rating speech transmission performance with or without sound systems. The STITEL method has more restricted uses. This fourth edition cancels and replaces the third edition, published in 2003, and constitutes a technical revision. It includes the following significant technical changes with respect to the previous edition: - development of more comprehensive, complete and unambiguous standardization of the STI methodology; - the term STIr is discontinued. A new function for the prediction of auditory masking effects is introduced; - the concept of 'speech level' and the setting of the level of the test signal have been introduced; - additional information has been included on prediction and measurement procedures. The French version of this standard has not been voted upon.

Elektroakustische Geräte - Teil 16: Objektive Bewertung der Sprachverständlichkeit durch den Sprachübertragungsindex

Equipements pour systèmes électroacoustiques - Partie 16: Evaluation objective de l'intelligibilité de la parole au moyen de l'indice de transmission de la parole

La CEI 60268-16:2011 spécifie des méthodes objectives d'évaluation de la qualité de transmission de la parole sous l'angle de l'intelligibilité. Elle met un manuel complet à la disposition de tous les types d'utilisateurs de la méthode STI dans les domaines de l'audio, des communications et de l'acoustique. Trois méthodes, étroitement liées, sont présentées sous le nom de STI, STIPA, et STITEL. Les deux premières méthodes sont destinées à l'évaluation des performances de la transmission de la parole avec ou sans systèmes électroacoustiques. La méthode STITEL a des utilisations plus restreintes. Cette quatrième édition annule et remplace la troisième édition parue en 2003, et constitue une révision technique. Elle inclut les modifications techniques importantes suivantes par rapport à l'édition précédente: - Le développement d'une normalisation plus aboutie, plus complète et moins ambiguë de la méthodologie STI; - le terme STIr n'est plus utilisé. Une nouvelle fonction pour la prédiction des effets du masquage auditif est introduite; - le concept de "niveau de parole" et le réglage du niveau du signal d'essai ont été introduits; - des informations supplémentaires relatives aux modes opératoires de prédiction et de mesures ont été incluses. La version française de cette norme n'a pas été soumise au vote.

Oprema za zvokovne sisteme - 16. del: Objektivno ocenjevanje govorne razumljivosti z uporabo indeksa prenosa govora (IEC 60268-16:2011)

Ta del IEC 60268 določa objektivne metode za ocenjevanje kakovosti prenosa govora z zvezi z razumljivostjo.
Cilj tega standarda je zagotoviti celosten priročnik za vse vrste uporabnikov
metode STI pri slušnosti komunikaciji in akustiki.
Ta standard ne zagotavlja kriterijev STI za certifikacijo kanalov prenosa (npr. kriterijev za sistem glas-alarm).
Predstavljene so tri metode, ki so tesno povezane in so omenjene kot STI, STIPA in STITEL. Prvi dve metodi sta namenjeni ocenjevanju delovanja prenosa govora
z zvokovnimi sistemi ali brez njih.
Uporabe metode STITEL so bolj omejene.
OPOMBA: Nobena izmed teh metod ni primerna za merjenje in ocenitev zasebnosti govora in sistemov za maskiranje govora, ker STI ni bil potrjen za zahteve, ki predstavljajo uporabe za zasebnost govora [1]1.
Vključene so naslednje informacije:
• tehnike merjenja;
• tehnike napovedovanja.

General Information

• Status: Withdrawn
• Publication Date: 25-Aug-2011
• Withdrawal Date: 01-Aug-2014
• ICS: 33.160.01 - Audio, video and audiovisual systems in general
• Technical Committee: CLC/TC 100X - Audio, video and multimedia systems and equipment and related sub-systems
• Drafting Committee: IEC/TC 100 - IEC_TC_100
• Parallel Committee: IEC/TC 100 - IEC_TC_100
• Current Stage: 9960 - Withdrawal effective - Withdrawal
• Start Date: 30-Oct-2023
• Completion Date: 30-Oct-2023
• Ref Project: SIST EN 60268-16:2011 - Sound system equipment - Part 16: Objective rating of speech intelligibility by speech transmission index (IEC 60268-16:2011)

Relations

• Replaces: EN 60268-16:2003 - Sound system equipment - Part 16: Objective rating of speech intelligibility by speech transmission index
• Effective Date: 28-Jan-2023
• Replaced By: EN IEC 60268-16:2020 - Sound system equipment - Part 16: Objective rating of speech intelligibility by speech transmission index
• Effective Date: 09-Jan-2018

Standards Content (Sample)

SLOVENSKI STANDARD
01-november-2011
1DGRPHãþD
SIST EN 60268-16:2003
Oprema za zvokovne sisteme - 16. del: Objektivno ocenjevanje govorne
razumljivosti z uporabo indeksa prenosa govora (IEC 60268-16:2011)
Sound system equipment - Part 16: Objective rating of speech intelligibility by speech
transmission index (IEC 60268-16:2011)
Elektroakustische Geräte - Teil 16: Objektive Bewertung der Sprachverständlichkeit
durch den Sprachübertragungsindex (IEC 60268-16:2011)
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Ta slovenski standard je istoveten z: EN 60268-16:2011
ICS:
33.160.30 Avdio sistemi Audio systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 60268-16
NORME EUROPÉENNE
August 2011
EUROPÄISCHE NORM
ICS 33.160.01 Supersedes EN 60268-16:2003

English version
Sound system equipment -
Part 16: Objective rating of speech intelligibility by speech transmission
index
(IEC 60268-16:2011)
Equipements pour systèmes Elektroakustische Geräte -
électroacoustiques - Teil 16: Objektive Bewertung der
Partie 16: Evaluation objective de Sprachverständlichkeit durch den
l'intelligibilité de la parole au moyen de Sprachübertragungsindex
l'indice de transmission de la parole (IEC 60268-16:2011)
(CEI 60268-16:2011)
This European Standard was approved by CENELEC on 2011-08-02. CENELEC 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 Central Secretariat or to any CENELEC 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 CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

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

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Management Centre: Avenue Marnix 17, B - 1000 Brussels

© 2011 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60268-16:2011 E
Foreword
The text of document 100/1812/FDIS, future edition 4 of IEC 60268-16, prepared by IEC TC 100, Audio,
video and multimedia systems and equipment, was submitted to the IEC-CENELEC parallel vote and was
approved by CENELEC as EN 60268-16 on 2011-08-02.
This European Standard supersedes EN 60268-16:2003.
— development of more comprehensive, complete and unambiguous standardization of the STI
methodology;
— the term STI is discontinued. A new function for the prediction of auditory masking effects is
r
introduced;
— the concept of 'speech level' and the setting of the level of the test signal have been introduced;
— additional information has been included on prediction and measurement procedures.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent
rights.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
(dop) 2012-05-02
national standard or by endorsement
– latest date by which the national standards conflicting
(dow) 2014-08-02
with the EN have to be withdrawn
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60268-16:2011 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
[2] IEC 60318-1:2009 NOTE  Harmonized as EN 60318-1:2009 (not modified).
[3] IEC 61672 series NOTE  Harmonized in EN 61672 series.
[37] ISO 7029:2000 NOTE  Harmonized as EN ISO 7029:2000.
[44] ISO 3382-1:2009 NOTE  Harmonized as EN ISO 3382-1:2009.
__________
- 3 - EN 60268-16:2011
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year

IEC 61260 1995 Electroacoustics - Octave-band EN 61260 1995
+ A1 2001 and fractional-octave-band filters + A1 2001

ISO 18233 2006 Acoustics - Application of new EN ISO 18233 2006
measurement methods in building and room
acoustics
IEC 60268-16 ®
Edition 4.0 2011-06
INTERNATIONAL
STANDARD
Sound system equipment –
Part 16: Objective rating of speech intelligibility by speech transmission index

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XB
ICS 33.160.01 ISBN 978-2-88912-522-7

– 2 – 60268-16  IEC:2011(E)
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 9
4 Description of the STI method . 15
4.1 General . 15
4.1.1 Rationale for the STI method . 15
4.1.2 Applicability of the STI method . 15
4.2 Background of the STI method . 16
4.2.1 General . 16
4.2.2 Theoretical overview . 17
4.2.3 Measurement of STI . 18
4.3 Applicability of STI test methods . 19
4.4 Use of direct and indirect methods . 20
4.5 Limitations of the STI method . 21
4.5.1 General . 21
4.5.2 Frequency shifts . 21
4.5.3 Centre clipping . 22
4.5.4 Drop outs . 22
4.5.5 Jitter . 22
4.5.6 Vocoders . 22
4.5.7 Overestimation of STI under low background noise conditions . 22
4.5.8 Frequency response . 22
4.5.9 Echoes . 23
4.5.10 Fast amplitude compression and expansion . 23
4.5.11 Non-linear distortion . 24
4.5.12 Impulsive and fluctuating noise . 24
4.5.13 Hearing impaired listeners . 24
4.6 Conclusion . 24
5 Direct method of measuring STI . 24
5.1 Overview . 24
5.2 STIPA . 25
5.3 Application . 26
5.4 Limitations . 26
6 Indirect method of measuring STI using the impulse response . 26
6.1 Overview . 26
6.2 Application . 27
6.3 Limitations (non-linear distortion) . 28
7 Measurement procedures, post-processing of data and applications . 28
7.1 General . 28
7.2 Acoustical input . 28
7.3 Acoustical output . 30
7.4 Electrical input . 30
7.5 Electrical output . 30
7.6 Examples of input/output combinations. 30

60268-16  IEC:2011(E) – 3 –
7.6.1 Acoustical input – Acoustical output . 30
7.6.2 Electrical input – Electrical output (e.g. assessment of wired and
wireless) communication systems) . 30
7.6.3 Acoustical input – Electrical output (e.g. assessment of microphones) . 31
7.6.4 Electrical input – Acoustical output (e.g. assessment of PA systems) . 31
7.7 Post-processing of measured MTF data . 31
7.8 Issues concerning noise . 31
7.8.1 General . 31
7.8.2 Measurement of background noise . 32
7.8.3 Fluctuating noise . 32
7.9 Analysis and interpretation of the results . 32
7.10 Binaural STI measurements . 33
8 Use of STI as a design prediction tool . 33
8.1 Overview . 33
8.2 Statistical predictions . 33
8.3 Prediction from simulated impulse response . 34
Annex A (normative) Speech transmission index (STI) and revised STI methods . 35
Annex B (normative) STIPA method . 47
Annex C (normative) STITEL method . 48
Annex D (informative) RASTI method (obsolete) . 49
Annex E (informative) Qualification of the STI and relationships with other speech
intelligibility measures. 51
Annex F (informative) Nominal qualification bands for STI . 53
Annex G (informative
...