GB/T 12060.16-2017Sound system equipment -- Part 16: Objective rating of speech intelligibility by speech transmission index (English PDF)

Foreword

GB/T 12060 "Acoustic System Equipment" has released or plans to release the following sections.

--- Part 1. Overview;

--- Part 2. General terminology and calculation methods;

--- Part 3. Audio amplifier measurement methods;

--- Part 4. Microphone measurement methods;

--- Part 5. Speaker main performance testing methods;

--- Part 6. Auxiliary passive components;

--- Part 7. Headphones and headphones measurement methods;

--- Part 8. Automatic gain control device;

--- Part 9. Artificial reverberation, time delay and frequency shift device measurement methods;

--- Part 10. Peak program meter;

--- Part 11. Application of connectors for acoustic system equipment interconnection;

--- Part 12. Application of connectors for broadcasting and similar sound systems;

--- Part 13. Speaker listening test;

--- Part 14. Round and oval speakers, dimensions and installation dimensions;

--- Part 16. objective evaluation of speech intelligibility through voice transmission index;

--- Part 17. Standard sound meter;

--- Part 18. Peak Program Meter - Digital Audio Peak Meter.

This section GB/T 12060 Part 16.

This section drafted in accordance with GB/T 1.1-2009 given rules.

This Part replaces GB/T 14476-1993 "objective assessment of the Office of the language intelligibility" RASTI "Act and GB/T 15485-1995 "Calculation method of acoustic language definition index", compared with GB/T 14476-1993 and GB/T 15485-1995, the main technical changes as follows.

--- Use the complete STI method, as well as two simplified forms of the complete STI method, STIPA and STITEL, instead of RASTI Law and Clarity Index (AI) methods (see Chapter 4, Chapter 5, Chapter 6 and Appendix A, Appendix B, Appendix C).

This section uses the redrafted law to amend the use of IEC 60268-16:2011 "Sound System Equipment Part 16. Through the voice transmission index Objective evaluation of speech intelligibility ".

This part of IEC 60268-16:2011 technical differences and the reasons are as follows.

--- Clear reference speech sound level measurements in the free field to avoid the impact of reflected sound (see 3.16);

--- Correct the modulation frequency in IEC 60268-16:2011 The expression "F" is "fm" (see 4.2.1, 4.2.2);

--- Based on the existing research, this part is used to objectively evaluate the applicability of Chinese verbal intelligibility explained (see 4.6);

--- Correct the IEC 60268-16:2011 corresponding to the impulse response square printing missing problem [see equation (4)];

--- Based on the latest literature, the importance of equalizing the frequency response of the test sound source (system) has been supplemented to avoid the resulting comparison Large measurement error [see 7.2 b]);

--- Based on the latest literature, the importance of testing the directivity of the sound source has been supplemented to avoid the resulting large measurement error Poor [see 7.2 c)];

--- Clarified that in measuring the speech intelligibility of natural sounding rooms and halls, the sound level of the test signal is calibrated in a free field (see 7.6.1);

--- Correct the "Chebyshev II filter" in IEC 60268-16:2011 as "Chebyshev I filter", the original Wrong (see A.4.2);

--- Correct IEC 60268-16:2011 in the "intensity modulation I" for the "modulation transfer ratio", the original text is wrong [see A.5.1.1 c)];

--- Removed Appendix D of IEC 60268-16:2011;

--- Correct IEC 60268-16:2011 "auditory masking factor amf" as "auditory masking level amdB", the original text is wrong [see

Table L.1, 2), 3)];

--- Correct the "MTIk, f" in IEC 60268-16:2011 as "TIk, f" with the original text [4c in Table L.1]).

Please note that some of this document may be patentable. The issuing agencies of this document do not bear the responsibility of identifying these patents.

This section is proposed by the Chinese Academy of Sciences.

This part of the National Acoustic Standardization Technical Committee (SAC/TC17) and the National Audio, Video and Multimedia Systems and Equipment Standardization Technical Committee (SAC/TC242) Common.

This part of the drafting unit. Dalian University of Technology, Tongji University, China Electronics Technology Group Corporation Institute of the Third Institute of Acoustics Institute, Peking University, South China University of Technology, Harbin Institute of Technology.

Introduction

The Speech Transmission Index (STI) is an objective measure of the intelligibility of a speaker's speech that arrives at the listener through the transmission path.

STI method has been put forward since the 1970s, has been in the process of improvement and development. With the continuous revision of IEC 60268-16, the major improvements of the STI approach have been integrated to provide a broad, complete and clear STI technical standard.

Speech is the main means of communication between people. In many cases, the speech signal is affected by the signal path between the speaker and the listener or transmission path, resulting in a decrease in speech intelligibility at the listener's location. To determine the speech intelligibility after passing through the transmission path the degree of reduction, a rapid and objective measurement method has been developed, namely the voice transmission index (STI). By specifying the transmission path of the test signal, and then analyze the received signal to derive the transmission quality of the transmission path and use the value between 0 to 1, which is STI. Based on the STI value, the possible verbal intelligibility of the transmission path can be determined. Although the STI method still has some limitations, it is also proved Ming is very effective under many conditions.

STI can be used to measure speech intelligibility in a variety of different electronic systems and acoustic environments. Typical applications include.

a) Measurement of public address systems and sound reinforcement systems;

b) measurement and identification of voice alarm system and emergency notification system;

c) Measurement and qualification of communication circuits (systems), such as internal and wireless communication systems;

d) measure speech intelligibility of rooms and halls (natural sound or sound reinforcement system);

e) evaluate direct verbal communication (without the use of PA systems), including rooms and various acoustic environments (eg in transport);

f) Speech comprehension evaluation of hearing aid systems.

Note. The STI method does not measure and evaluate verbal privacy or speech masking systems.

STI users come from all walks of life and potential users may include.

a) appraisers of voice alarm systems and other types of emergency notification systems;

b) appraisers of sound reinforcement systems and audio systems;

c) Manufacturer of audio and wireless communication equipment;

d) Audio and Communication Engineer;

e) Acoustics and electroacoustic engineers;

f) Installer of the audio system;

g) Researcher of STI method and developer of STI measuring instrument.

To avoid misinterpretation of STI results, users understand the rationale, scope, and limitations of STI measurement methods is very important.

Sound system equipment - Part 16. Transmission by voice Index objective assessment of speech intelligibility

1 Scope

This part of GB/T 12060 specifies the objective evaluation method of speech transmission quality related to intelligibility, including measurement techniques and pre Measuring technology.

This section presents three methods that are closely related and are STI, STIPA, and STITEL. The first two methods are mainly used to evaluate the quality of voice transmission with or without audio system conditions, STITEL's conditions are subject to more stringent restrictions.

NOTE None of the above methods are suitable for measuring and evaluating speech privacy and speech masking systems because STI methods are not used under conditions of speech privacy Verification [15].

This section applies to the public address system and sound reinforcement system, voice alarm system and emergency notification system, communication circuit (system), natural sound or rooms and halls using sound reinforcement systems, direct verbal communication, and speech transmission index measurements and predictions for hearing aid systems.

This section does not provide STI evaluation criteria for transmission path qualification (for example, what is the STI for a voice alarm system?

qualified).

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated version applies to this article Pieces. For undated references, the latest edition (including all amendments) applies to this document.

Electroacoustics octave and fractional octave filters (IEC 61260:1995, MOD) GB/T 3241-2010 Application of new methods of measurement in acoustic building acoustics and room acoustics - MLS and SS methods (ISO 18233-2010).

2006, IDT)

3 Terms and definitions

The following terms and definitions apply to this document.

Speech intelligibility Evaluation of the proportion of speech is understood.

Speech quality Voice quality of voice signal evaluation.

Speech transmission index; STI the metric between 0 and 1 represents the voice transmission quality associated with the intelligibility of the voice transmission path.

Speech intelligibility index speechinteligibilityindex; SII Objective intelligibility prediction method developed from the articulation index.

STI method (full STI) STImethod (FULLSTI) the objective method of measuring and predicting the speech transmission index is to modulate in 7 octaves using 14 modulation frequencies.