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
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
RES/STQ-251
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
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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
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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
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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.
TM
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
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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
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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
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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)".
th
NOTE: Proceedings of the 12 International Congress on Acoustics. Toronto published on behalf of the
th
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
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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
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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
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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.
st
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
nd
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.
TM
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
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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)".
th
NOTE: Proceedings of the 12 International Congress on Acoustics. Toronto published on behalf of the
th
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.
st
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
nd
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]DGMDGHO 6LPXODFLMVNDWHKQLNDãXPDR]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
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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)".
th
NOTE: Proceedings of the 12 International Congress on Acoustics. Toronto published on behalf of the
th
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".
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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).
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• 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
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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.
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4.3 IOSONO
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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.
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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
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