Speech and multimedia Transmission Quality (STQ) - Speech quality performance in the presence of background noise - Part 1: Background noise simulation technique and background noise database

The quality of background noise transmission is an important factor, which significantly contributes to the perceived
overall quality of speech. Existing and even more the new generation of terminals, networks and system configurations
including broadband services can be greatly improved with a proper design of terminals and systems in the presence of
background noise. The present document:
• describes a noise simulation environment using realistic background noise scenarios for laboratory use;
• contains a database including the relevant background noise samples for subjective and objective evaluation.
The present document provides information about the recording techniques needed for background noise recordings and
discusses the advantages and drawbacks of existing methods. The present document describes the requirements for
laboratory conditions. The loudspeaker setup and the loudspeaker calibration and equalization procedure are described.
The simulation environment specified can be used for the evaluation and optimization of terminals and of complex
configurations including terminals, networks and other configurations. The main application areas should be: office,
home and car environment.
The setup and database as described in the present document are applicable for:
• Objective performance evaluation of terminals in different (simulated) background noise environments.
• Speech processing evaluation by using the pre-processed speech signal in the presence of background noise,
recorded by a terminal.
• Subjective evaluation of terminals by performing conversational tests, specific double talk tests or talking and
listening tests in the presence of background noise.
• Subjective evaluation in third party listening tests by recording the speech samples of terminals in the presence
of background noise.

Kakovost prenosa govora in večpredstavnih vsebin (STQ) - Kakovost govora v prisotnosti šuma ozadja - 1. del: Simulacijska tehnika šuma ozadja in podatkovna zbirka šumov ozadja

Kakovost prenosa šuma ozadja je pomemben dejavnik, ki bistveno prispeva k sprejeti celotni kakovosti govora. Obstoječo in še bolj novo generacijo terminalov, omrežij in konfiguracij sistemov, vključno s širokopasovnimi storitvami, je mogoče znatno izboljšati s pravilnim projektiranjem terminalov in sistemov ob prisotnosti šuma ozadja. Ta dokument:
• vsebuje opis okolja za simulacijo šuma, v katerem so uporabljeni realistični scenariji za šum ozadja za laboratorijsko uporabo;
• vsebuje zbirko podatkov, vključno z relevantnimi vzorci šuma ozadja za subjektivno in objektivno vrednotenje.
V trenutnem dokumentu so zagotovljene informacije o tehnikah zapisovanja, ki so potrebne za zapisovanje šuma ozadja, in obravnavane so prednosti in pomanjkljivosti obstoječih metod. V trenutnem dokumentu so opisane zahteve za laboratorijske pogoje. Opisani so postopki nastavljanja zvočnikov ter umerjanja zvočnikov in izenačevanja temperature.
Določeno simulacijsko okolje je mogoče uporabiti za vrednotenje in optimizacijo terminalov in zapletenih konfiguracij, vključno s terminali, omrežji in drugimi konfiguracijami. Glavna območja uporabe morajo biti: pisarna,
domače okolje in avtomobil.
Namestitev in zbirka podatkov, kot sta opisani v trenutnem dokumentu, se uporabljata za naslednje:
• objektivno vrednotenje delovanja terminalov v različnih (simuliranih) okoljih s šumom ozadja;
• vrednotenje obdelave govora s predhodno obdelanim govornim signalom ob prisotnosti šuma ozadja,
ki ga zapiše terminal;
• subjektivno vrednotenje terminalov na podlagi izvedbe pogovornih testov, specifičnih testov dvojnih prenosov ali testov oddajanja in prejemanja ob prisotnosti šuma ozadja;
• subjektivno vrednotenje preskusov prejemanja tretjih oseb z zapisovanjem vzorcev govora terminalov ob prisotnosti šuma ozadja.

General Information

Status
Published
Publication Date
26-Mar-2018
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
19-Mar-2018
Due Date
24-May-2018
Completion Date
27-Mar-2018

Buy Standard

Standard
ETSI ES 202 396-1 V1.7.1 (2017-10) - Speech and multimedia Transmission Quality (STQ); Speech quality performance in the presence of background noise; Part 1: Background noise simulation technique and background noise database
English language
62 pages
sale 15% off
Preview
sale 15% off
Preview
Standard
ETSI ES 202 396-1 V1.7.1 (2017-08) - Speech and multimedia Transmission Quality (STQ); Speech quality performance in the presence of background noise; Part 1: Background noise simulation technique and background noise database
English language
62 pages
sale 15% off
Preview
sale 15% off
Preview
Standardization document
SIST ES 202 396-1 V1.7.1:2018
English language
62 pages
sale 10% off
Preview
sale 10% off
Preview

e-Library read for
1 day

Standards Content (sample)

ETSI ES 202 396-1 V1.7.1 (2017-10)
ETSI STANDARD
Speech and multimedia Transmission Quality (STQ);
Speech quality performance
in the presence of background noise;
Part 1: Background noise simulation technique
and background noise database
---------------------- Page: 1 ----------------------
2 ETSI ES 202 396-1 V1.7.1 (2017-10)
Reference
RES/STQ-251
Keywords
noise, performance, quality, speech
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE
Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16
Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88
Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search

The present document may be made available in electronic versions and/or in print. The content of any electronic and/or

print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any

existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the

print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat.

Users of the present document should be aware that the document may be subject to revision or change of status.

Information on the current status of this and other ETSI documents is available at

https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx

If you find errors in the present document, please send your comment to one of the following services:

https://portal.etsi.org/People/CommiteeSupportStaff.aspx
Copyright Notification

No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying

and microfilm except as authorized by written permission of ETSI.

The content of the PDF version shall not be modified without the written authorization of ETSI.

The copyright and the foregoing restriction extend to reproduction in all media.
© ETSI 2017.
All rights reserved.
TM TM TM

DECT , PLUGTESTS , UMTS and the ETSI logo are trademarks of ETSI registered for the benefit of its Members.

3GPP and LTE™ are trademarks of ETSI registered for the benefit of its Members and

of the 3GPP Organizational Partners.
oneM2M logo is protected for the benefit of its Members.

GSM® and the GSM logo are trademarks registered and owned by the GSM Association.

ETSI
---------------------- Page: 2 ----------------------
3 ETSI ES 202 396-1 V1.7.1 (2017-10)
Contents

Intellectual Property Rights ................................................................................................................................ 5

Foreword ............................................................................................................................................................. 5

Modal verbs terminology .................................................................................................................................... 5

Introduction ........................................................................................................................................................ 5

1 Scope ........................................................................................................................................................ 6

2 References ................................................................................................................................................ 6

2.1 Normative references ......................................................................................................................................... 6

2.2 Informative references ........................................................................................................................................ 6

3 Definitions and abbreviations ................................................................................................................... 8

3.1 Definitions .......................................................................................................................................................... 8

3.2 Abbreviations ..................................................................................................................................................... 8

4 Overview of existing methods for realistic sound reproduction............................................................... 8

4.1 Introduction ........................................................................................................................................................ 8

4.2 Surround Sound Techniques............................................................................................................................... 9

4.3 IOSONO ......................................................................................................................................................... 10

4.4 Eidophonie ....................................................................................................................................................... 10

4.5 Four-loudspeaker arrangement for playback of binaurally recorded signals .................................................... 11

4.6 NTT Background-Noise Database ................................................................................................................... 12

4.7 General conclusions ......................................................................................................................................... 12

5 Recording arrangement .......................................................................................................................... 13

5.1 Binaural equalization ........................................................................................................................................ 13

5.2 The equalization procedure .............................................................................................................................. 13

6 Loudspeaker Setup for Background Noise Simulation .......................................................................... 15

6.1 Test Room Requirements ................................................................................................................................. 15

6.2 Loudspeaker Positioning .................................................................................................................................. 15

6.3 Equalization and Calibration ............................................................................................................................ 16

6.4 Accuracy of the reproduction arrangement ...................................................................................................... 22

6.4.0 Introduction................................................................................................................................................. 22

6.4.1 Comparison between original sound field and simulated sound field ......................................................... 22

6.4.2 Displacement of the test arrangement in the simulated sound field ............................................................ 23

6.4.3 Transmission of background noise: Comparison of terminal performance in the original sound field

and the simulated sound field ..................................................................................................................... 25

6.5 Simulation of additional acoustic conditions .................................................................................................... 29

7 Background Noise Simulation in cars .................................................................................................... 30

7.1 General setup .................................................................................................................................................... 30

7.2 Recording arrangement .................................................................................................................................... 31

7.2.0 Introduction................................................................................................................................................. 31

7.2.1 Recording setup with the terminal's microphone ........................................................................................ 31

7.2.2 Recording setup with a pair of cardioid microphones................................................................................. 32

7.3 Equalization and Calibration with the terminal's microphone .......................................................................... 32

7.4 Equalization and Calibration with a pair of cardioid microphones .................................................................. 37

7.5 Accuracy of the reproduction arrangement ...................................................................................................... 42

7.5.1 Comparison between original sound field and simulated sound field ......................................................... 42

7.5.2 Transmission of background noise: Comparison of terminal performance in the original sound field

and the simulated sound field ..................................................................................................................... 43

8 Background Noise Database .................................................................................................................. 46

8.0 Introduction ...................................................................................................................................................... 46

8.1 Binaural signals ................................................................................................................................................ 46

8.2 Binaural signals identical to the background noise recordings provided in ETSI TS 103 224 ......................... 49

8.3 Stereophonic signals ......................................................................................................................................... 50

ETSI
---------------------- Page: 3 ----------------------
4 ETSI ES 202 396-1 V1.7.1 (2017-10)

Annex A (informative): Comparison of Tests in Sending Direction and D-Values Conducted

in Different Rooms ......................................................................................... 51

A.0 Introduction ............................................................................................................................................ 51

A.1 Test Setup ............................................................................................................................................... 51

A.2 Results of the Tests ................................................................................................................................ 52

A.2.0 Introduction ...................................................................................................................................................... 52

A.2.1 Sending Frequency Response Characteristics and SLR ................................................................................... 52

A.2.2 D-Value with Pink Noise ................................................................................................................................. 52

A.2.3 D-Value with Cafeteria Noise .......................................................................................................................... 53

A.3 Conclusions ............................................................................................................................................ 53

Annex B (informative): Graphs ............................................................................................................ 54

History .............................................................................................................................................................. 62

ETSI
---------------------- Page: 4 ----------------------
5 ETSI ES 202 396-1 V1.7.1 (2017-10)
Intellectual Property Rights
Essential patents

IPRs essential or potentially essential to the present document may have been declared to ETSI. The information

pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found

in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in

respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web

server (https://ipr.etsi.org/).

Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee

can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web

server) which are, or may be, or may become, essential to the present document.
Trademarks

The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.

ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no

right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does

not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.

Foreword

This ETSI Standard (ES) has been produced by ETSI Technical Committee Speech and multimedia Transmission

Quality (STQ).

The present document is part 1 of a multi-part deliverable covering Speech and multimedia Transmission Quality

(STQ); Speech quality performance in the presence of background noise, as identified below:

ETSI ES 202 396-1: "Background noise simulation technique and background noise database";

ETSI EG 202 396-2: "Background noise transmission - Network simulation - Subjective test database and results";

ETSI EG 202 396-3: "Background noise transmission - Objective test methods".
Modal verbs terminology

In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and

"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of

provisions).

"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

Introduction

Background noise is present in most of the conversations today. Background noise may impact the speech

communication performance to terminal and network equipment significantly. Therefore testing and optimization of

such equipment is necessary using realistic background noises. Furthermore reproducible conditions for the tests are

required which can be guaranteed only under lab type condition.

The present document addresses this issue by describing a methodology for recording and playback of background

noises under well-defined and calibratable conditions in a lab-type environment. Furthermore a database with real

background noises is included.
ETSI
---------------------- Page: 5 ----------------------
6 ETSI ES 202 396-1 V1.7.1 (2017-10)
1 Scope

The quality of background noise transmission is an important factor, which significantly contributes to the perceived

overall quality of speech. Existing and even more the new generation of terminals, networks and system configurations

including broadband services can be greatly improved with a proper design of terminals and systems in the presence of

background noise. The present document:

• describes a noise simulation environment using realistic background noise scenarios for laboratory use;

• contains a database including the relevant background noise samples for subjective and objective evaluation.

The present document provides information about the recording techniques needed for background noise recordings and

discusses the advantages and drawbacks of existing methods. The present document describes the requirements for

laboratory conditions. The loudspeaker setup and the loudspeaker calibration and equalization procedure are described.

The simulation environment specified can be used for the evaluation and optimization of terminals and of complex

configurations including terminals, networks and other configurations. The main application areas should be: office,

home and car environment.
The setup and database as described in the present document are applicable for:

• Objective performance evaluation of terminals in different (simulated) background noise environments.

• Speech processing evaluation by using the pre-processed speech signal in the presence of background noise,

recorded by a terminal.

• Subjective evaluation of terminals by performing conversational tests, specific double talk tests or talking and

listening tests in the presence of background noise.

• Subjective evaluation in third party listening tests by recording the speech samples of terminals in the presence

of background noise.
2 References
2.1 Normative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

Referenced documents which are not found to be publicly available in the expected location might be found at

https://docbox.etsi.org/Reference.

NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee

their long term validity.

The following referenced documents are necessary for the application of the present document.

Not applicable.
2.2 Informative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee

their long term validity.
ETSI
---------------------- Page: 6 ----------------------
7 ETSI ES 202 396-1 V1.7.1 (2017-10)

The following referenced documents are not necessary for the application of the present document but they assist the

user with regard to a particular subject area.

[i.1] Surround Sound Past, Present, and Future: "A history of multichannel audio from mag stripe to

Dolby Digital", Joseph Hull - Dolby Laboratories Inc.

[i.2] AES preprint 3332 (1992): "Improved Possibilities of Binaural Recording and Playback

Techniques", K. Genuit, H.W. Gierlich; U. Künzli.
NOTE: Available at http://www.aes.org/e-lib/browse.cfm?elib=6801.

[i.3] AES preprint 3732 (1993): "A System for the Reproduction Technique for Playback of Binaural

Recordings", N. Xiang, K. Genuit, H.W. Gierlich.
NOTE: Available at http://www.aes.org/e-lib/browse.cfm?elib=6501.
[i.4] NTTAT Database: "Ambient Noise Database CD-ROM".
NOTE: Available at http://www.ntt-at.com/product/noise-DB.

[i.5] ISO 11904-1: "Acoustics - Determination of sound imission from sound sources placed close to

the ear - Part 1: Technique using a microphone in a real ear (MIRE technique)".

[i.6] Spatial Hearing: "The psychophysics of human sound localization", J. Blauert.

[i.7] Recommendation ITU-T P.57: "Artificial ears".
[i.8] Recommendation ITU-T P.58: "Head and torso simulator for telephonometry".

[i.9] Recommendation ITU-T P.340: "Transmission characteristics and speech quality parameters of

hands-free terminals".

[i.10] Recommendation ITU-T P.64: "Determination of sensitivity/frequency characteristics of local

telephone systems".
[i.11] Recommendation ITU-T G.722: "7 kHz audio-coding within 64 kbit/s".

[i.12] Genuit, K.: "A Description of the Human Outer Ear Transfer Function by Elements of

Communication Theory (No. B6-8)".

NOTE: Proceedings of the 12 International Congress on Acoustics. Toronto published on behalf of the

Technical Program Committee by the Executive Committee of the 12 International Congress on

Acoustics.

[i.13] IEC 60050-722: "International Electrotechnical Vocabulary - Chapter 722: Telephony".

[i.14] "Wellenfeldsynthese - Eine neue Dimension der 3D-Audiowiedergabe"; Fernseh- und

Kino-Technik, Nr. 11/2002, pp. 735-738.
[i.15] "The Iosono Sound Difference".
NOTE: Available at http://www.iosono-sound.de.

[i.16] "Ein neues Verfahren der raumbezogenen Stereophonie mit verbesserter Übertragung der

Rauminformation"; P. Scherer, Rundfunktechnische Mitteilungen, 1977, pp. 196-204.

[i.17] ETSI EG 202 396-1 (V1.1.2): "Speech Processing, Transmission and Quality Aspects (STQ);

Speech quality performance in the presence of background noise; Part 1: Background noise

simulation technique and background noise database".

[i.18] ETSI TS 151 010-1: "Digital cellular telecommunications system (Phase 2+); Mobile Station (MS)

conformance specification; Part 1: Conformance specification (3GPP TS 51.010-1)".

[i.19] ETSI TS 103 224: "Speech and multimedia Transmission Quality (STQ); A sound field

reproduction method for terminal testing including a background noise database".
ETSI
---------------------- Page: 7 ----------------------
8 ETSI ES 202 396-1 V1.7.1 (2017-10)
3 Definitions and abbreviations
3.1 Definitions

For the purposes of the present document, the following terms and definitions apply:

crosstalk: appearance of undesired energy in a channel, owing to the presence of a signal in another channel, caused

by, for example induction, conduction or non-linearity
NOTE: See IEC 60050-722 [i.13].
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
CD Compact Disc
EQ Equalization
FFT Fast Fourier Transform
FIR Finite Impulse Response
HATS Head And Torso Simulator
IIR Infinite Impulse Response
MIRE Microphone In Real Ear
MRP Mouth Reference Point
NTT Nippon Telegraph and Telephone corporation
SLR Send Loudness Rating
VHF Very High Frequency
4 Overview of existing methods for realistic sound
reproduction
4.1 Introduction

In general the existing methods for close to original sound recording and reproduction aimed for different applications:

• Techniques intending to reproduce the actual sound field.

• Techniques providing hearing adequate (ear related) signals in the human ear canal.

• Techniques generating artificial acoustical environments.

Within this clause the different methods are briefly described and their applicability for close to original sound-filed

reproduction is discussed. A variety of methods have been studied, in the following a summary of the most important

ones relevant to the present document is given. The different methods were analysed on the basis of the following

requirements:
• The background noise recording technique should be:
- easy to use;
- easy to calibrate;
- capable of wideband recording;
- available at reasonable costs;

- mostly compatible to existing standards and procedures used in telecommunications testing;

- applicable to different environments (at least office, home and car).
ETSI
---------------------- Page: 8 ----------------------
9 ETSI ES 202 396-1 V1.7.1 (2017-10)
• The background noise simulation arrangement should:
- be easy to setup;
- not require any specific acoustical treatment for the simulation requirement;

- provide a mostly realistic background noise simulation for all typical background noises faced with in

telecommunication applications;
- be easy to calibrate;

- be mostly insensitive against the positioning of (test)-objects in the simulated sound field;

- be applicable to all typical terminals used in telecommunication;
- be available at reasonable costs.
4.2 Surround Sound Techniques

The basics of surround techniques are found in cinema applications. The virtual image provided by stereophonic

presentation of sounds seemed not to be sufficient for the large screen display in cinema. In the 1950s 4-channel and

6-channel soundtracks recorded on magnetic stripes associated to the films were developed, 4-channel and 6-channel

loudspeaker systems were installed in cinemas to reproduce the multichannel sounds. The newer techniques were

mostly developed and marketed by Dolby [i.1]: Dolby Surround, Dolby Surround Pro Logic, Dolby Digital and Dolby

Digital Surround are examples for the techniques introduced more recently. The most common configuration is the

"5.1-configuration" used in cinema but in home applications as well. The reproduction system consists of left and right

channel, a centre speaker, two surround channels (left and right, arranged in the back of the listener) and a low

frequency channel for low frequency effects.

The aim of all surround system is to create an artificial acoustical image in the recording studio rather than recording a

real acoustical scenario and providing true to original playback possibilities.

On the recording side special surround encoders are used allowing the 5-channel signal to be encoded from a special

mixing console to the 5.1 digital data stream. The playback system consists of a special decoder allowing to separate the

5 channels again and distribute them on the 5.1 loudspeaker playback system. The systems are mono and stereo

compatible and can handle the older 4-channel surround techniques by a specific decoder.

Applications:

Typical applications for surround systems are cinemas and home theatres. The source material is produced by

professional recording studios using multi-channel mixing consoles and specific 5.1 decoding techniques. In mostly all

cases virtual environments are created which support the visual image by an appropriate acoustical image.

Conclusion:

Surround techniques are designed for creating acoustical images rather than for close to original recording and

reproduction. Although the spatial impression provided by surround techniques is sometimes remarkable the acoustical

image created is always artificial. Due to the lack of easy to use recording techniques allowing a spatial recording of a

sound field surround sound techniques are not suitable for creation of a background noise database with realistic

background noises and calibrated background noise simulation in a lab.
ETSI
---------------------- Page: 9 ----------------------
10 ETSI ES 202 396-1 V1.7.1 (2017-10)
4.3 IOSONO

The IOSONO sound system (see [i.14], [i.15] and [i.16]) is based on the Wave-Field Synthesis. It employs Huygens

principle of wave theory. Applied to acoustics this principle means that it is possible to reproduce any form of wave

front with an array of loudspeakers, so that virtual sound sources can be placed anywhere within a listening area. For

practical use it is necessary to position loudspeakers all-round the playback room. In order to generate realistic sound

fields the input signal for each loudspeaker has to be calculated separately. For this purpose each single sound source

(e.g. voices) has to be recorded individually. If the recordings are done in a room, the characteristics (like reverberation)

of the recording room also have to be recorded separately. All resulting sound tracks are then mixed and manipulated

during the post-editing process and the reproduction.

The natural and realistic spatial sound reproduction is then achieved in a wide area of the play back room. Common 5.1

stereo systems achieve a "realistic" sound reproduction only in a small area of the reproduction room.

Applications:

Typical applications are sound systems for home use, cinemas and other entertainment events. The IOSONO sound

system is also able to play back recordings made in common stereo or 5.1 stereo techniques.

Conclusion:

The drawbacks of this method are the components needed: a sophisticated recording system, a powerful computing unit

for real-time mixing the large number of recorded sound tracks and the number of loudspeakers that have to be installed

in the listening room. In a common size cinema for example about 200 loudspeakers are needed.

The advantage is that with the IOSONO sound system a very realistic sound reproduction is possible, but it requires an

enormous effort, which is too high for daily use in laboratories.
4.4 Eidophonie

This method (see [i.17]) was developed for realistic sound reproduction using the VHF transmission technique. The

main principle is to separate the base signal from the part of the signal, which contains the information about the

direction of sound incidence.

For recording a 1 order gradient microphone with a cardioid directivity is used. During the recordings its directivity

rotates with 38 kHz in the recording plane. This "turning microphone" provides an amplitude-modulated signal at its

electrical output. The resulting side bands are out of the transmitted frequency range. But these side bands contain the

information of the direction of sound incidence. Using the VHF- transmission techniques this phase information can be

transmitted within the 2 audio-frequency channel.

The sound reproduction is made by a spatial demodulation: a switch is positioned before each loudspeaker and each

switches synchronously with the turning directivity. So a low pass filtered short-term section of the signal containing

the information of the direction of sound incidence is played back on each loudspeaker. The loudspeakers are positioned

all around the playback room.
Applications:
Eidophonie was developed to provide a realistic sound envi
...

Final draft ETSI ES 202 396-1 V1.7.1 (2017-08)
ETSI STANDARD
Speech and multimedia Transmission Quality (STQ);
Speech quality performance
in the presence of background noise;
Part 1: Background noise simulation technique
and background noise database
---------------------- Page: 1 ----------------------
2 Final draft ETSI ES 202 396-1 V1.7.1 (2017-08)
Reference
RES/STQ-251
Keywords
noise, performance, quality, speech
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE
Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16
Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88
Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search

The present document may be made available in electronic versions and/or in print. The content of any electronic and/or

print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any

existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the

print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat.

Users of the present document should be aware that the document may be subject to revision or change of status.

Information on the current status of this and other ETSI documents is available at

https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx

If you find errors in the present document, please send your comment to one of the following services:

https://portal.etsi.org/People/CommiteeSupportStaff.aspx
Copyright Notification

No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying

and microfilm except as authorized by written permission of ETSI.

The content of the PDF version shall not be modified without the written authorization of ETSI.

The copyright and the foregoing restriction extend to reproduction in all media.
© ETSI 2017.
All rights reserved.
TM TM TM

DECT , PLUGTESTS , UMTS and the ETSI logo are trademarks of ETSI registered for the benefit of its Members.

3GPP and LTE™ are trademarks of ETSI registered for the benefit of its Members and

of the 3GPP Organizational Partners.
oneM2M logo is protected for the benefit of its Members.

GSM® and the GSM logo are trademarks registered and owned by the GSM Association.

ETSI
---------------------- Page: 2 ----------------------
3 Final draft ETSI ES 202 396-1 V1.7.1 (2017-08)
Contents

Intellectual Property Rights ................................................................................................................................ 5

Foreword ............................................................................................................................................................. 5

Modal verbs terminology .................................................................................................................................... 5

Introduction ........................................................................................................................................................ 5

1 Scope ........................................................................................................................................................ 6

2 References ................................................................................................................................................ 6

2.1 Normative references ......................................................................................................................................... 6

2.2 Informative references ........................................................................................................................................ 6

3 Definitions and abbreviations ................................................................................................................... 8

3.1 Definitions .......................................................................................................................................................... 8

3.2 Abbreviations ..................................................................................................................................................... 8

4 Overview of existing methods for realistic sound reproduction............................................................... 8

4.1 Introduction ........................................................................................................................................................ 8

4.2 Surround Sound Techniques............................................................................................................................... 9

4.3 IOSONO ........................................................................................................................................................ 10

4.4 Eidophonie ....................................................................................................................................................... 10

4.5 Four-loudspeaker arrangement for playback of binaurally recorded signals .................................................... 11

4.6 NTT Background-Noise Database ................................................................................................................... 12

4.7 General conclusions ......................................................................................................................................... 12

5 Recording arrangement .......................................................................................................................... 13

5.1 Binaural equalization ........................................................................................................................................ 13

5.2 The equalization procedure .............................................................................................................................. 13

6 Loudspeaker Setup for Background Noise Simulation .......................................................................... 15

6.1 Test Room Requirements ................................................................................................................................. 15

6.2 Loudspeaker Positioning .................................................................................................................................. 15

6.3 Equalization and Calibration ............................................................................................................................ 16

6.4 Accuracy of the reproduction arrangement ...................................................................................................... 22

6.4.0 Introduction................................................................................................................................................. 22

6.4.1 Comparison between original sound field and simulated sound field ......................................................... 22

6.4.2 Displacement of the test arrangement in the simulated sound field ............................................................ 23

6.4.3 Transmission of background noise: Comparison of terminal performance in the original sound field

and the simulated sound field ..................................................................................................................... 25

6.5 Simulation of additional acoustic conditions .................................................................................................... 29

7 Background Noise Simulation in cars .................................................................................................... 30

7.1 General setup .................................................................................................................................................... 30

7.2 Recording arrangement .................................................................................................................................... 31

7.2.0 Introduction................................................................................................................................................. 31

7.2.1 Recording setup with the terminal's microphone ........................................................................................ 31

7.2.2 Recording setup with a pair of cardioid microphones................................................................................. 32

7.3 Equalization and Calibration with the terminal's microphone .......................................................................... 32

7.4 Equalization and Calibration with a pair of cardioid microphones .................................................................. 37

7.5 Accuracy of the reproduction arrangement ...................................................................................................... 42

7.5.1 Comparison between original sound field and simulated sound field ......................................................... 42

7.5.2 Transmission of background noise: Comparison of terminal performance in the original sound field

and the simulated sound field ..................................................................................................................... 43

8 Background Noise Database .................................................................................................................. 46

8.0 Introduction ...................................................................................................................................................... 46

8.1 Binaural signals ................................................................................................................................................ 46

8.2 Binaural signals identical to the background noise recordings provided in ETSI TS 103 224 ......................... 49

8.3 Stereophonic signals ......................................................................................................................................... 50

ETSI
---------------------- Page: 3 ----------------------
4 Final draft ETSI ES 202 396-1 V1.7.1 (2017-08)

Annex A (informative): Comparison of Tests in Sending Direction and D-Values Conducted

in Different Rooms ......................................................................................... 51

A.0 Introduction ............................................................................................................................................ 51

A.1 Test Setup ............................................................................................................................................... 51

A.2 Results of the Tests ................................................................................................................................ 52

A.2.0 Introduction ...................................................................................................................................................... 52

A.2.1 Sending Frequency Response Characteristics and SLR ................................................................................... 52

A.2.2 D-Value with Pink Noise ................................................................................................................................. 52

A.2.3 D-Value with Cafeteria Noise .......................................................................................................................... 53

A.3 Conclusions ............................................................................................................................................ 53

Annex B (informative): Graphs ............................................................................................................ 54

History .............................................................................................................................................................. 62

ETSI
---------------------- Page: 4 ----------------------
5 Final draft ETSI ES 202 396-1 V1.7.1 (2017-08)
Intellectual Property Rights
Essential patents

IPRs essential or potentially essential to the present document may have been declared to ETSI. The information

pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found

in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in

respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web

server (https://ipr.etsi.org/).

Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee

can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web

server) which are, or may be, or may become, essential to the present document.
Trademarks

The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.

ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no

right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does

not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.

Foreword

This final draft ETSI Standard (ES) has been produced by ETSI Technical Committee Speech and multimedia

Transmission Quality (STQ), and is now submitted for the ETSI standards Membership Approval Procedure.

The present document is part 1 of a multi-part deliverable covering Speech and multimedia Transmission Quality

(STQ); Speech quality performance in the presence of background noise, as identified below:

ETSI ES 202 396-1: "Background noise simulation technique and background noise database";

ETSI EG 202 396-2: "Background noise transmission - Network simulation - Subjective test database and results";

ETSI EG 202 396-3: "Background noise transmission - Objective test methods".
Modal verbs terminology

In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and

"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of

provisions).

"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

Introduction

Background noise is present in most of the conversations today. Background noise may impact the speech

communication performance to terminal and network equipment significantly. Therefore testing and optimization of

such equipment is necessary using realistic background noises. Furthermore reproducible conditions for the tests are

required which can be guaranteed only under lab type condition.

The present document addresses this issue by describing a methodology for recording and playback of background

noises under well-defined and calibratable conditions in a lab-type environment. Furthermore a database with real

background noises is included.
ETSI
---------------------- Page: 5 ----------------------
6 Final draft ETSI ES 202 396-1 V1.7.1 (2017-08)
1 Scope

The quality of background noise transmission is an important factor, which significantly contributes to the perceived

overall quality of speech. Existing and even more the new generation of terminals, networks and system configurations

including broadband services can be greatly improved with a proper design of terminals and systems in the presence of

background noise. The present document:

• describes a noise simulation environment using realistic background noise scenarios for laboratory use;

• contains a database including the relevant background noise samples for subjective and objective evaluation.

The present document provides information about the recording techniques needed for background noise recordings and

discusses the advantages and drawbacks of existing methods. The present document describes the requirements for

laboratory conditions. The loudspeaker setup and the loudspeaker calibration and equalization procedure are described.

The simulation environment specified can be used for the evaluation and optimization of terminals and of complex

configurations including terminals, networks and other configurations. The main application areas should be: office,

home and car environment.
The setup and database as described in the present document are applicable for:

• Objective performance evaluation of terminals in different (simulated) background noise environments.

• Speech processing evaluation by using the pre-processed speech signal in the presence of background noise,

recorded by a terminal.

• Subjective evaluation of terminals by performing conversational tests, specific double talk tests or talking and

listening tests in the presence of background noise.

• Subjective evaluation in third party listening tests by recording the speech samples of terminals in the presence

of background noise.
2 References
2.1 Normative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

Referenced documents which are not found to be publicly available in the expected location might be found at

https://docbox.etsi.org/Reference.

NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee

their long term validity.

The following referenced documents are necessary for the application of the present document.

Not applicable.
2.2 Informative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee

their long term validity.
ETSI
---------------------- Page: 6 ----------------------
7 Final draft ETSI ES 202 396-1 V1.7.1 (2017-08)

The following referenced documents are not necessary for the application of the present document but they assist the

user with regard to a particular subject area.

[i.1] Surround Sound Past, Present, and Future: "A history of multichannel audio from mag stripe to

Dolby Digital", Joseph Hull - Dolby Laboratories Inc.

[i.2] AES preprint 3332 (1992): "Improved Possibilities of Binaural Recording and Playback

Techniques", K. Genuit, H.W. Gierlich; U. Künzli.
NOTE: Available at http://www.aes.org/e-lib/browse.cfm?elib=6801.

[i.3] AES preprint 3732 (1993): "A System for the Reproduction Technique for Playback of Binaural

Recordings", N. Xiang, K. Genuit, H.W. Gierlich.
NOTE: Available at http://www.aes.org/e-lib/browse.cfm?elib=6501.
[i.4] NTTAT Database: "Ambient Noise Database CD-ROM".
NOTE: Available at http://www.ntt-at.com/product/noise-DB.

[i.5] ISO 11904-1: "Acoustics - Determination of sound imission from sound sources placed close to

the ear - Part 1: Technique using a microphone in a real ear (MIRE technique)".

[i.6] Spatial Hearing: "The psychophysics of human sound localization", J. Blauert.

[i.7] Recommendation ITU-T P.57: "Artificial ears".
[i.8] Recommendation ITU-T P.58: "Head and torso simulator for telephonometry".

[i.9] Recommendation ITU-T P.340: "Transmission characteristics and speech quality parameters of

hands-free terminals".

[i.10] Recommendation ITU-T P.64: "Determination of sensitivity/frequency characteristics of local

telephone systems".
[i.11] Recommendation ITU-T G.722: "7 kHz audio-coding within 64 kbit/s".

[i.12] Genuit, K.: "A Description of the Human Outer Ear Transfer Function by Elements of

Communication Theory (No. B6-8)".

NOTE: Proceedings of the 12 International Congress on Acoustics. Toronto published on behalf of the

Technical Program Committee by the Executive Committee of the 12 International Congress on

Acoustics.

[i.13] IEC 60050-722: "International Electrotechnical Vocabulary - Chapter 722: Telephony".

[i.14] "Wellenfeldsynthese - Eine neue Dimension der 3D-Audiowiedergabe"; Fernseh- und

Kino-Technik, Nr. 11/2002, pp. 735-738.
[i.15] "The Iosono Sound Difference".
NOTE: Available at http://www.iosono-sound.de.

[i.16] "Ein neues Verfahren der raumbezogenen Stereophonie mit verbesserter Übertragung der

Rauminformation"; P. Scherer, Rundfunktechnische Mitteilungen, 1977, pp. 196-204.

[i.17] ETSI EG 202 396-1 (V1.1.2): "Speech Processing, Transmission and Quality Aspects (STQ);

Speech quality performance in the presence of background noise; Part 1: Background noise

simulation technique and background noise database".

[i.18] ETSI TS 151 010-1: "Digital cellular telecommunications system (Phase 2+); Mobile Station (MS)

conformance specification; Part 1: Conformance specification (3GPP TS 51.010-1)".

[i.19] ETSI TS 103 224: "Speech and multimedia Transmission Quality (STQ); A sound field

reproduction method for terminal testing including a background noise database".
ETSI
---------------------- Page: 7 ----------------------
8 Final draft ETSI ES 202 396-1 V1.7.1 (2017-08)
3 Definitions and abbreviations
3.1 Definitions

For the purposes of the present document, the following terms and definitions apply:

crosstalk: appearance of undesired energy in a channel, owing to the presence of a signal in another channel, caused

by, for example induction, conduction or non-linearity
NOTE: See IEC 60050-722 [i.13].
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
CD Compact Disc
EQ Equalization
FFT Fast Fourier Transform
FIR Finite Impulse Response
HATS Head And Torso Simulator
IIR Infinite Impulse Response
MIRE Microphone In Real Ear
MRP Mouth Reference Point
NTT Nippon Telegraph and Telephone corporation
SLR Send Loudness Rating
VHF Very High Frequency
4 Overview of existing methods for realistic sound
reproduction
4.1 Introduction

In general the existing methods for close to original sound recording and reproduction aimed for different applications:

• Techniques intending to reproduce the actual sound field.

• Techniques providing hearing adequate (ear related) signals in the human ear canal.

• Techniques generating artificial acoustical environments.

Within this clause the different methods are briefly described and their applicability for close to original sound-filed

reproduction is discussed. A variety of methods have been studied, in the following a summary of the most important

ones relevant to the present document is given. The different methods were analysed on the basis of the following

requirements:
• The background noise recording technique should be:
- easy to use;
- easy to calibrate;
- capable of wideband recording;
- available at reasonable costs;

- mostly compatible to existing standards and procedures used in telecommunications testing;

- applicable to different environments (at least office, home and car).
ETSI
---------------------- Page: 8 ----------------------
9 Final draft ETSI ES 202 396-1 V1.7.1 (2017-08)
• The background noise simulation arrangement should:
- be easy to setup;
- not require any specific acoustical treatment for the simulation requirement;

- provide a mostly realistic background noise simulation for all typical background noises faced with in

telecommunication applications;
- be easy to calibrate;

- be mostly insensitive against the positioning of (test)-objects in the simulated sound field;

- be applicable to all typical terminals used in telecommunication;
- be available at reasonable costs.
4.2 Surround Sound Techniques

The basics of surround techniques are found in cinema applications. The virtual image provided by stereophonic

presentation of sounds seemed not to be sufficient for the large screen display in cinema. In the 1950s 4-channel and

6-channel soundtracks recorded on magnetic stripes associated to the films were developed, 4-channel and 6-channel

loudspeaker systems were installed in cinemas to reproduce the multichannel sounds. The newer techniques were

mostly developed and marketed by Dolby [i.1]: Dolby Surround, Dolby Surround Pro Logic, Dolby Digital and Dolby

Digital Surround are examples for the techniques introduced more recently. The most common configuration is the

"5.1-configuration" used in cinema but in home applications as well. The reproduction system consists of left and right

channel, a centre speaker, two surround channels (left and right, arranged in the back of the listener) and a low

frequency channel for low frequency effects.

The aim of all surround system is to create an artificial acoustical image in the recording studio rather than recording a

real acoustical scenario and providing true to original playback possibilities.

On the recording side special surround encoders are used allowing the 5-channel signal to be encoded from a special

mixing console to the 5.1 digital data stream. The playback system consists of a special decoder allowing to separate the

5 channels again and distribute them on the 5.1 loudspeaker playback system. The systems are mono and stereo

compatible and can handle the older 4-channel surround techniques by a specific decoder.

Applications:

Typical applications for surround systems are cinemas and home theatres. The source material is produced by

professional recording studios using multi-channel mixing consoles and specific 5.1 decoding techniques. In mostly all

cases virtual environments are created which support the visual image by an appropriate acoustical image.

Conclusion:

Surround techniques are designed for creating acoustical images rather than for close to original recording and

reproduction. Although the spatial impression provided by surround techniques is sometimes remarkable the acoustical

image created is always artificial. Due to the lack of easy to use recording techniques allowing a spatial recording of a

sound field surround sound techniques are not suitable for creation of a background noise database with realistic

background noises and calibrated background noise simulation in a lab.
ETSI
---------------------- Page: 9 ----------------------
10 Final draft ETSI ES 202 396-1 V1.7.1 (2017-08)
4.3 IOSONO

The IOSONO sound system (see [i.14], [i.15] and [i.16]) is based on the Wave-Field Synthesis. It employs Huygens

principle of wave theory. Applied to acoustics this principle means that it is possible to reproduce any form of wave

front with an array of loudspeakers, so that virtual sound sources can be placed anywhere within a listening area. For

practical use it is necessary to position loudspeakers all-round the playback room. In order to generate realistic sound

fields the input signal for each loudspeaker has to be calculated separately. For this purpose each single sound source

(e.g. voices) has to be recorded individually. If the recordings are done in a room, the characteristics (like reverberation)

of the recording room also have to be recorded separately. All resulting sound tracks are then mixed and manipulated

during the post-editing process and the reproduction.

The natural and realistic spatial sound reproduction is then achieved in a wide area of the play back room. Common 5.1

stereo systems achieve a "realistic" sound reproduction only in a small area of the reproduction room.

Applications:

Typical applications are sound systems for home use, cinemas and other entertainment events. The IOSONO sound

system is also able to play back recordings made in common stereo or 5.1 stereo techniques.

Conclusion:

The drawbacks of this method are the components needed: a sophisticated recording system, a powerful computing unit

for real-time mixing the large number of recorded sound tracks and the number of loudspeakers that have to be installed

in the listening room. In a common size cinema for example about 200 loudspeakers are needed.

The advantage is that with the IOSONO sound system a very realistic sound reproduction is possible, but it requires an

enormous effort, which is too high for daily use in laboratories.
4.4 Eidophonie

This method (see [i.17]) was developed for realistic sound reproduction using the VHF transmission technique. The

main principle is to separate the base signal from the part of the signal, which contains the information about the

direction of sound incidence.

For recording a 1 order gradient microphone with a cardioid directivity is used. During the recordings its directivity

rotates with 38 kHz in the recording plane. This "turning microphone" provides an amplitude-modulated signal at its

electrical output. The resulting side bands are out of the transmitted frequency range. But these side bands contain the

information of the direction of sound incidence. Using the VHF- transmission techniques this phase information can be

transmitted within the 2 audio-frequency channel.

The sound reproduction is made by a spatial demodulation: a switch is positioned before each loudspeaker and each

switches synchronously with the turning directivity. So a low pass filtered short-term section of the signal containing

the inform
...

SLOVENSKI STANDARD
SIST ES 202 396-1 V1.7.1:2018
01-maj-2018
.DNRYRVWSUHQRVDJRYRUDLQYHþSUHGVWDYQLKYVHELQ 674 .DNRYRVWJRYRUDY
SULVRWQRVWLãXPDR]DGMDGHO6LPXODFLMVNDWHKQLNDãXPDR]DGMDLQSRGDWNRYQD
]ELUNDãXPRYR]DGMD

Speech and multimedia Transmission Quality (STQ) - Speech quality performance in the

presence of background noise - Part 1: Background noise simulation technique and
background noise database
Ta slovenski standard je istoveten z: ETSI ES 202 396-1 V1.7.1 (2017-10)
ICS:
33.040.35 Telefonska omrežja Telephone networks
SIST ES 202 396-1 V1.7.1:2018 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST ES 202 396-1 V1.7.1:2018
---------------------- Page: 2 ----------------------
SIST ES 202 396-1 V1.7.1:2018
ETSI ES 202 396-1 V1.7.1 (2017-10)
ETSI STANDARD
Speech and multimedia Transmission Quality (STQ);
Speech quality performance
in the presence of background noise;
Part 1: Background noise simulation technique
and background noise database
---------------------- Page: 3 ----------------------
SIST ES 202 396-1 V1.7.1:2018
2 ETSI ES 202 396-1 V1.7.1 (2017-10)
Reference
RES/STQ-251
Keywords
noise, performance, quality, speech
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE
Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16
Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88
Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search

The present document may be made available in electronic versions and/or in print. The content of any electronic and/or

print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any

existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the

print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat.

Users of the present document should be aware that the document may be subject to revision or change of status.

Information on the current status of this and other ETSI documents is available at

https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx

If you find errors in the present document, please send your comment to one of the following services:

https://portal.etsi.org/People/CommiteeSupportStaff.aspx
Copyright Notification

No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying

and microfilm except as authorized by written permission of ETSI.

The content of the PDF version shall not be modified without the written authorization of ETSI.

The copyright and the foregoing restriction extend to reproduction in all media.
© ETSI 2017.
All rights reserved.
TM TM TM

DECT , PLUGTESTS , UMTS and the ETSI logo are trademarks of ETSI registered for the benefit of its Members.

3GPP and LTE™ are trademarks of ETSI registered for the benefit of its Members and

of the 3GPP Organizational Partners.
oneM2M logo is protected for the benefit of its Members.

GSM® and the GSM logo are trademarks registered and owned by the GSM Association.

ETSI
---------------------- Page: 4 ----------------------
SIST ES 202 396-1 V1.7.1:2018
3 ETSI ES 202 396-1 V1.7.1 (2017-10)
Contents

Intellectual Property Rights ................................................................................................................................ 5

Foreword ............................................................................................................................................................. 5

Modal verbs terminology .................................................................................................................................... 5

Introduction ........................................................................................................................................................ 5

1 Scope ........................................................................................................................................................ 6

2 References ................................................................................................................................................ 6

2.1 Normative references ......................................................................................................................................... 6

2.2 Informative references ........................................................................................................................................ 6

3 Definitions and abbreviations ................................................................................................................... 8

3.1 Definitions .......................................................................................................................................................... 8

3.2 Abbreviations ..................................................................................................................................................... 8

4 Overview of existing methods for realistic sound reproduction............................................................... 8

4.1 Introduction ........................................................................................................................................................ 8

4.2 Surround Sound Techniques............................................................................................................................... 9

4.3 IOSONO ......................................................................................................................................................... 10

4.4 Eidophonie ....................................................................................................................................................... 10

4.5 Four-loudspeaker arrangement for playback of binaurally recorded signals .................................................... 11

4.6 NTT Background-Noise Database ................................................................................................................... 12

4.7 General conclusions ......................................................................................................................................... 12

5 Recording arrangement .......................................................................................................................... 13

5.1 Binaural equalization ........................................................................................................................................ 13

5.2 The equalization procedure .............................................................................................................................. 13

6 Loudspeaker Setup for Background Noise Simulation .......................................................................... 15

6.1 Test Room Requirements ................................................................................................................................. 15

6.2 Loudspeaker Positioning .................................................................................................................................. 15

6.3 Equalization and Calibration ............................................................................................................................ 16

6.4 Accuracy of the reproduction arrangement ...................................................................................................... 22

6.4.0 Introduction................................................................................................................................................. 22

6.4.1 Comparison between original sound field and simulated sound field ......................................................... 22

6.4.2 Displacement of the test arrangement in the simulated sound field ............................................................ 23

6.4.3 Transmission of background noise: Comparison of terminal performance in the original sound field

and the simulated sound field ..................................................................................................................... 25

6.5 Simulation of additional acoustic conditions .................................................................................................... 29

7 Background Noise Simulation in cars .................................................................................................... 30

7.1 General setup .................................................................................................................................................... 30

7.2 Recording arrangement .................................................................................................................................... 31

7.2.0 Introduction................................................................................................................................................. 31

7.2.1 Recording setup with the terminal's microphone ........................................................................................ 31

7.2.2 Recording setup with a pair of cardioid microphones................................................................................. 32

7.3 Equalization and Calibration with the terminal's microphone .......................................................................... 32

7.4 Equalization and Calibration with a pair of cardioid microphones .................................................................. 37

7.5 Accuracy of the reproduction arrangement ...................................................................................................... 42

7.5.1 Comparison between original sound field and simulated sound field ......................................................... 42

7.5.2 Transmission of background noise: Comparison of terminal performance in the original sound field

and the simulated sound field ..................................................................................................................... 43

8 Background Noise Database .................................................................................................................. 46

8.0 Introduction ...................................................................................................................................................... 46

8.1 Binaural signals ................................................................................................................................................ 46

8.2 Binaural signals identical to the background noise recordings provided in ETSI TS 103 224 ......................... 49

8.3 Stereophonic signals ......................................................................................................................................... 50

ETSI
---------------------- Page: 5 ----------------------
SIST ES 202 396-1 V1.7.1:2018
4 ETSI ES 202 396-1 V1.7.1 (2017-10)

Annex A (informative): Comparison of Tests in Sending Direction and D-Values Conducted

in Different Rooms ......................................................................................... 51

A.0 Introduction ............................................................................................................................................ 51

A.1 Test Setup ............................................................................................................................................... 51

A.2 Results of the Tests ................................................................................................................................ 52

A.2.0 Introduction ...................................................................................................................................................... 52

A.2.1 Sending Frequency Response Characteristics and SLR ................................................................................... 52

A.2.2 D-Value with Pink Noise ................................................................................................................................. 52

A.2.3 D-Value with Cafeteria Noise .......................................................................................................................... 53

A.3 Conclusions ............................................................................................................................................ 53

Annex B (informative): Graphs ............................................................................................................ 54

History .............................................................................................................................................................. 62

ETSI
---------------------- Page: 6 ----------------------
SIST ES 202 396-1 V1.7.1:2018
5 ETSI ES 202 396-1 V1.7.1 (2017-10)
Intellectual Property Rights
Essential patents

IPRs essential or potentially essential to the present document may have been declared to ETSI. The information

pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found

in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in

respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web

server (https://ipr.etsi.org/).

Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee

can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web

server) which are, or may be, or may become, essential to the present document.
Trademarks

The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.

ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no

right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does

not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.

Foreword

This ETSI Standard (ES) has been produced by ETSI Technical Committee Speech and multimedia Transmission

Quality (STQ).

The present document is part 1 of a multi-part deliverable covering Speech and multimedia Transmission Quality

(STQ); Speech quality performance in the presence of background noise, as identified below:

ETSI ES 202 396-1: "Background noise simulation technique and background noise database";

ETSI EG 202 396-2: "Background noise transmission - Network simulation - Subjective test database and results";

ETSI EG 202 396-3: "Background noise transmission - Objective test methods".
Modal verbs terminology

In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and

"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of

provisions).

"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

Introduction

Background noise is present in most of the conversations today. Background noise may impact the speech

communication performance to terminal and network equipment significantly. Therefore testing and optimization of

such equipment is necessary using realistic background noises. Furthermore reproducible conditions for the tests are

required which can be guaranteed only under lab type condition.

The present document addresses this issue by describing a methodology for recording and playback of background

noises under well-defined and calibratable conditions in a lab-type environment. Furthermore a database with real

background noises is included.
ETSI
---------------------- Page: 7 ----------------------
SIST ES 202 396-1 V1.7.1:2018
6 ETSI ES 202 396-1 V1.7.1 (2017-10)
1 Scope

The quality of background noise transmission is an important factor, which significantly contributes to the perceived

overall quality of speech. Existing and even more the new generation of terminals, networks and system configurations

including broadband services can be greatly improved with a proper design of terminals and systems in the presence of

background noise. The present document:

• describes a noise simulation environment using realistic background noise scenarios for laboratory use;

• contains a database including the relevant background noise samples for subjective and objective evaluation.

The present document provides information about the recording techniques needed for background noise recordings and

discusses the advantages and drawbacks of existing methods. The present document describes the requirements for

laboratory conditions. The loudspeaker setup and the loudspeaker calibration and equalization procedure are described.

The simulation environment specified can be used for the evaluation and optimization of terminals and of complex

configurations including terminals, networks and other configurations. The main application areas should be: office,

home and car environment.
The setup and database as described in the present document are applicable for:

• Objective performance evaluation of terminals in different (simulated) background noise environments.

• Speech processing evaluation by using the pre-processed speech signal in the presence of background noise,

recorded by a terminal.

• Subjective evaluation of terminals by performing conversational tests, specific double talk tests or talking and

listening tests in the presence of background noise.

• Subjective evaluation in third party listening tests by recording the speech samples of terminals in the presence

of background noise.
2 References
2.1 Normative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

Referenced documents which are not found to be publicly available in the expected location might be found at

https://docbox.etsi.org/Reference.

NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee

their long term validity.

The following referenced documents are necessary for the application of the present document.

Not applicable.
2.2 Informative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee

their long term validity.
ETSI
---------------------- Page: 8 ----------------------
SIST ES 202 396-1 V1.7.1:2018
7 ETSI ES 202 396-1 V1.7.1 (2017-10)

The following referenced documents are not necessary for the application of the present document but they assist the

user with regard to a particular subject area.

[i.1] Surround Sound Past, Present, and Future: "A history of multichannel audio from mag stripe to

Dolby Digital", Joseph Hull - Dolby Laboratories Inc.

[i.2] AES preprint 3332 (1992): "Improved Possibilities of Binaural Recording and Playback

Techniques", K. Genuit, H.W. Gierlich; U. Künzli.
NOTE: Available at http://www.aes.org/e-lib/browse.cfm?elib=6801.

[i.3] AES preprint 3732 (1993): "A System for the Reproduction Technique for Playback of Binaural

Recordings", N. Xiang, K. Genuit, H.W. Gierlich.
NOTE: Available at http://www.aes.org/e-lib/browse.cfm?elib=6501.
[i.4] NTTAT Database: "Ambient Noise Database CD-ROM".
NOTE: Available at http://www.ntt-at.com/product/noise-DB.

[i.5] ISO 11904-1: "Acoustics - Determination of sound imission from sound sources placed close to

the ear - Part 1: Technique using a microphone in a real ear (MIRE technique)".

[i.6] Spatial Hearing: "The psychophysics of human sound localization", J. Blauert.

[i.7] Recommendation ITU-T P.57: "Artificial ears".
[i.8] Recommendation ITU-T P.58: "Head and torso simulator for telephonometry".

[i.9] Recommendation ITU-T P.340: "Transmission characteristics and speech quality parameters of

hands-free terminals".

[i.10] Recommendation ITU-T P.64: "Determination of sensitivity/frequency characteristics of local

telephone systems".
[i.11] Recommendation ITU-T G.722: "7 kHz audio-coding within 64 kbit/s".

[i.12] Genuit, K.: "A Description of the Human Outer Ear Transfer Function by Elements of

Communication Theory (No. B6-8)".

NOTE: Proceedings of the 12 International Congress on Acoustics. Toronto published on behalf of the

Technical Program Committee by the Executive Committee of the 12 International Congress on

Acoustics.

[i.13] IEC 60050-722: "International Electrotechnical Vocabulary - Chapter 722: Telephony".

[i.14] "Wellenfeldsynthese - Eine neue Dimension der 3D-Audiowiedergabe"; Fernseh- und

Kino-Technik, Nr. 11/2002, pp. 735-738.
[i.15] "The Iosono Sound Difference".
NOTE: Available at http://www.iosono-sound.de.

[i.16] "Ein neues Verfahren der raumbezogenen Stereophonie mit verbesserter Übertragung der

Rauminformation"; P. Scherer, Rundfunktechnische Mitteilungen, 1977, pp. 196-204.

[i.17] ETSI EG 202 396-1 (V1.1.2): "Speech Processing, Transmission and Quality Aspects (STQ);

Speech quality performance in the presence of background noise; Part 1: Background noise

simulation technique and background noise database".

[i.18] ETSI TS 151 010-1: "Digital cellular telecommunications system (Phase 2+); Mobile Station (MS)

conformance specification; Part 1: Conformance specification (3GPP TS 51.010-1)".

[i.19] ETSI TS 103 224: "Speech and multimedia Transmission Quality (STQ); A sound field

reproduction method for terminal testing including a background noise database".
ETSI
---------------------- Page: 9 ----------------------
SIST ES 202 396-1 V1.7.1:2018
8 ETSI ES 202 396-1 V1.7.1 (2017-10)
3 Definitions and abbreviations
3.1 Definitions

For the purposes of the present document, the following terms and definitions apply:

crosstalk: appearance of undesired energy in a channel, owing to the presence of a signal in another channel, caused

by, for example induction, conduction or non-linearity
NOTE: See IEC 60050-722 [i.13].
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
CD Compact Disc
EQ Equalization
FFT Fast Fourier Transform
FIR Finite Impulse Response
HATS Head And Torso Simulator
IIR Infinite Impulse Response
MIRE Microphone In Real Ear
MRP Mouth Reference Point
NTT Nippon Telegraph and Telephone corporation
SLR Send Loudness Rating
VHF Very High Frequency
4 Overview of existing methods for realistic sound
reproduction
4.1 Introduction

In general the existing methods for close to original sound recording and reproduction aimed for different applications:

• Techniques intending to reproduce the actual sound field.

• Techniques providing hearing adequate (ear related) signals in the human ear canal.

• Techniques generating artificial acoustical environments.

Within this clause the different methods are briefly described and their applicability for close to original sound-filed

reproduction is discussed. A variety of methods have been studied, in the following a summary of the most important

ones relevant to the present document is given. The different methods were analysed on the basis of the following

requirements:
• The background noise recording technique should be:
- easy to use;
- easy to calibrate;
- capable of wideband recording;
- available at reasonable costs;

- mostly compatible to existing standards and procedures used in telecommunications testing;

- applicable to different environments (at least office, home and car).
ETSI
---------------------- Page: 10 ----------------------
SIST ES 202 396-1 V1.7.1:2018
9 ETSI ES 202 396-1 V1.7.1 (2017-10)
• The background noise simulation arrangement should:
- be easy to setup;
- not require any specific acoustical treatment for the simulation requirement;

- provide a mostly realistic background noise simulation for all typical background noises faced with in

telecommunication applications;
- be easy to calibrate;

- be mostly insensitive against the positioning of (test)-objects in the simulated sound field;

- be applicable to all typical terminals used in telecommunication;
- be available at reasonable costs.
4.2 Surround Sound Techniques

The basics of surround techniques are found in cinema applications. The virtual image provided by stereophonic

presentation of sounds seemed not to be sufficient for the large screen display in cinema. In the 1950s 4-channel and

6-channel soundtracks recorded on magnetic stripes associated to the films were developed, 4-channel and 6-channel

loudspeaker systems were installed in cinemas to reproduce the multichannel sounds. The newer techniques were

mostly developed and marketed by Dolby [i.1]: Dolby Surround, Dolby Surround Pro Logic, Dolby Digital and Dolby

Digital Surround are examples for the techniques introduced more recently. The most common configuration is the

"5.1-configuration" used in cinema but in home applications as well. The reproduction system consists of left and right

channel, a centre speaker, two surround channels (left and right, arranged in the back of the listener) and a low

frequency channel for low frequency effects.

The aim of all surround system is to create an artificial acoustical image in the recording studio rather than recording a

real acoustical scenario and providing true to original playback possibilities.

On the recording side special surround encoders are used allowing the 5-channel signal to be encoded from a special

mixing console to the 5.1 digital data stream. The playback system consists of a special decoder allowing to separate the

5 channels again and distribute them on the 5.1 loudspeaker playback system. The systems are mono and stereo

compatible and can handle the older 4-channel surround techniques by a specific decoder.

Applications:

Typical applications for surround systems are cinemas and home theatres. The source material is produced by

professional recording studios using multi-channel mixing consoles and specific 5.1 decoding techniques. In mostly all

cases virtual environments are created which support the visual image by an appropriate acoustical image.

Conclusion:

Surround techniques are designed for creating acoustical images rather than for close to original recording and

reproduction. Although the spatial impression provided by surround techniques is sometimes remarkable the acoustical

image created is always artificial. Due to the lack of easy to use recording techniques allowing a spatial recording of a

sound field surround sound techniques are not suitable for creation of a background noise database with realistic

background noises and calibrated background noise simulation in a lab.
ETSI
---------------------- Page: 11 ----------------------
SIST ES 202 396-1 V1.7.1:2018
10 ETSI ES 202 396-1 V1.7.1 (2017-10)
4.3 IOSONO

The IOSONO sound system (see [i.14], [i.15] and [i.16]) is based on the Wave-Field Synthesis. It employs Huygens

principle of wave theory. Applied to acoustics this principle means that it is possible to reproduce any form of wave

front with an array of loudspeakers, so that virtual sound sources can be placed anywhere within a listening area. For

practical use it is necessary to position loudspeakers all-round the playback room. In order to generate realistic sound

fields the input signal for each loudspeaker has to be calculated separately. For this purpose each single sound source

(e.g. voices) has to be recorded individually. If the recordings are done in a room, the characteristics (like reverberation)

of the recording room also have to be recorded separately. All resulting sound tracks are then mixed and manipulated

during the post-editing process and the reproduction.

The natural and realistic spatial sound reproduction is then achieved in a wide area of the play back room. Common 5.1

stereo systems achieve a "realistic" sound reproduction only in a small area of the reproduction room.

Applications:

Typical applications are sound systems for home use, cinemas and other entertainment events. The IOSONO sound

system is also able to play back recordings made in common stereo or 5.1 stereo techniques.

Conclusion:

The drawbacks of this method are the components needed: a sophisticated recording system, a powerful computing unit

for real-time mixing the large number of recorded sound tracks and the number of loudspeakers that have to be installed

in the listening room. In a common size cinema for example about 200 loudspeakers are needed.

The advantage is that with the IOSONO sound system a very realistic sound reproduction is possible, but it requires an

enormous effort, which is too high for daily use in laboratories.
4.4 Eidophonie
This method (see [i.17]) was developed for realistic sound repro
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.