1、 International Telecommunication Union ITU-T P.501TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (01/2012) SERIES P: TERMINALS AND SUBJECTIVE AND OBJECTIVE ASSESSMENT METHODS Objective measuring apparatus Test signals for use in telephonometry Recommendation ITU-T P.501 ITU-T P-SERIES RECOMMENDATIO
2、NS TERMINALS AND SUBJECTIVE AND OBJECTIVE ASSESSMENT METHODS Vocabulary and effects of transmission parameters on customer opinion of transmission quality Series P.10 Voice terminal characteristics Series P.30 P.300 Reference systems Series P.40 Objective measuring apparatus Series P.50P.500Objectiv
3、e electro-acoustical measurements Series P.60 Measurements related to speech loudness Series P.70 Methods for objective and subjective assessment of speech quality Series P.80 P.800 Audiovisual quality in multimedia services Series P.900 Transmission performance and QoS aspects of IP end-points Seri
4、es P.1000 Communications involving vehicles Series P.1100 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T P.501 (01/2012) i Recommendation ITU-T P.501 Test signals for use in telephonometry Summary Recommendation ITU-T P.501 describes test signals which are applica
5、ble for several purposes in telephonometry. This Recommendation gives a wide variety of test signals starting with low complexity test signals up to test signals with a high degree of complexity incorporating a lot of typical parameters of speech. Besides technical signals such as sine waves or nois
6、e, more speech-like signals are described. This Recommendation describes the principles of the signal construction for each type of test signal. Characteristic properties such as power density spectra, probability density functions or shaping filter responses are shown. This Recommendation gives an
7、overview about the typical application of the test signals described. This overview is a guideline giving general application rules. The detailed description of the application however should be found in the individual Recommendations describing the measurement procedures for a certain application.
8、In order to avoid problems in creating the test signals described, all these test signals are freely available for download from the ITU-T test signals database. Annex A proposes two test signals (a pn-sequence with a low crest factor and a logarithmically distributed multi-sine wave) for the measur
9、ement of terminal coupling loss (TCL). Annex B provides speech files and noise sequences to be used in combination with objective speech quality evaluation methods. This speech material does not replace the speech material found in Supplement 23 to ITU-T P-series Recommendations. Appendix I provides
10、 a description of the processing applied to the speech signals in clause 7.3. History Edition Recommendation Approval Study Group 1.0 ITU-T P.501 1996-08-30 12 2.0 ITU-T P.501 2000-05-18 12 2.1 ITU-T P.501 (2000) Amd. 1 2004-05-14 12 3.0 ITU-T P.501 2007-06-29 12 4.0 ITU-T P.501 2009-12-14 12 5.0 IT
11、U-T P.501 2012-01-13 12 5.1 ITU-T P.501 (2012) Amd. 1 2012-07-14 12 ii Rec. ITU-T P.501 (01/2012) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommu
12、nication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assem
13、bly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology whic
14、h fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with th
15、is Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory lang
16、uage such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this
17、Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date o
18、f approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TS
19、B patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2013 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T P.501 (01/2012) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 1 3.1 Te
20、rms defined elsewhere 1 3.2 Terms defined in this Recommendation . 2 4 Abbreviations and acronyms 2 5 Conventions 2 6 Overview of test signals and typical applications. 2 7 Types of test signals . 6 7.1 Non-speech-like (fully artificial) signals 6 7.2 Speech-like signals . 8 7.3 Speech signals 36 7.
21、4 Additional languages 46 Annex A Test signals for terminal coupling loss (TCL) tests. 52 Annex B Speech files and noise sequences 53 B.1 General . 53 B.2 Description of the recording procedure used for speech signals 53 B.3 Test sentences . 53 B.4 Noise sequences 58 Appendix I Description of the pr
22、ocessing applied to the speech signals in clause 7.3 . 61 I.1 Filter for DC removal . 61 I.2 Creation of the single-talk speech sequence . 61 I.3 Example high-pass filter designs 61 Bibliography. 63 Electronic attachment: Set of freely-available test signals described within the Recommendation.Rec.
23、ITU-T P.501 (01/2012) 1 Recommendation ITU-T P.501 Test signals for use in telephonometry 1 Scope This Recommendation describes test signals which are applicable for several purposes in telephonometry. A wide variety of test signals is given, starting with low complexity test signals up to test sign
24、als with a high degree of complexity incorporating a lot of typical parameters of speech. Besides technical signals such as sine waves or noise, more speech-like signals are described. The overview about the typical applications of the test signals described is a guideline giving general application
25、 rules. The detailed description of the application however should be found in individual Recommendations describing the measurement procedures for certain applications. In order to avoid problems in creating the test signals described, all these signals are freely available for download from the IT
26、U-T test signals database: http:/www.itu.int/net/itu-t/sigdb/genaudio/Pseries.htm#P.501. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editi
27、ons indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid
28、 ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.122 Recommendation ITU-T G.122 (1993), Influence of national systems on stability and talker echo in internationa
29、l connections. ITU-T G.168 Recommendation ITU-T G.168 (2012), Digital network echo cancellers. ITU-T G.191 Recommendation ITU-T G.191 (2010), Software tools for speech and audio coding standardization. ITU-T P.50 Recommendation ITU-T P.50 (1999), Artificial voices. ITU-T P.56 Recommendation ITU-T P.
30、56 (2011), Objective measurement of active speech level. ITU-T P.59 Recommendation ITU-T P.59 (1993), Artificial conversational speech. ITU-T P.79 Recommendation ITU-T P.79 (2007), Calculation of loudness ratings for telephone sets. ITU-T P.340 Recommendation ITU-T P.340 (2000), Transmission charact
31、eristics and speech quality parameters of hands-free terminals. ITU-T P.800 Recommendation ITU-T P.800 (1996), Methods for subjective determination of transmission quality. 3 Definitions 3.1 Terms defined elsewhere None. 2 Rec. ITU-T P.501 (01/2012) 3.2 Terms defined in this Recommendation This Reco
32、mmendation defines the following terms: 3.2.1 crest factor: Peak-to-RMS ratio of a signal. 3.2.2 composite source signal (CSS): Signal composed in time by various signal elements. 3.2.3 Markov speech model process (MSMP): Speech simulating signal using trainable Markov-chains for the generation of a
33、 speech-like signal, taking into account the generation process of real speech. 3.2.4 modulation transfer function (MTF): Modulation signal, derived from the envelope of a test signal. 3.2.5 pseudo noise sequence (PN-sequence): Pseudo-random noise with defined frequency-content, derived by inverse F
34、ourier transformation of a predefined frequency spectrum. 3.2.6 simulated speech generator (SSG): Signal offering speech-like properties, constructed taking into account the generation process of real speech. 3.2.7 speech transmission index (STI): Index indicating the speech intelligibility, especia
35、lly in reverberant conditions, derived from measuring the modulation transfer function. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: FFT Fast Fourier Transform LTI Linear Time-Invariant PDF Probability Density Function 5 Conventions None. 6 Overview
36、 of test signals and typical applications Linear, time-invariant systems (e.g., standard handset telephones without echo/noise cancelling) Sine wave (Note 1) Noise (Note 2) CSS (Note 3) Probetone SSG ITU-TP.50 ITU-T P.59 MSMP Speech Loudness ratings x x x x x x x x x Frequency responses x x x x x x
37、x x x Listener sidetone/ talker sidetone x x x x x x x x x Harmonic distortion x x Distortion x x Out-of-band signals x x Rec. ITU-T P.501 (01/2012) 3 Linear, time-invariant systems (e.g., standard handset telephones without echo/noise cancelling) Sine wave (Note 1) Noise (Note 2) CSS (Note 3) Probe
38、tone SSG ITU-TP.50 ITU-T P.59 MSMP Speech Level measurements x x x x x x x x x Delay measurements x x x (x) x (x) x Echo measurements x x x (x) (x) (x) (x) (x) x Applicable (x) Applicable with some caution NOTE 1 Including modulated sine wave and Fourier spectra. NOTE 2 Including pink, white and swi
39、tched noise. NOTE 3 Including various combinations of voiced sound and measurement signals (PN-sequence, sine, etc.). Non-linear and/or time-variant systems (e.g., mobile phones) Sine wave (Note 1) Noise (Note 2) CSS (Note 3)Probetone SSGITU-T P.50 ITU-T P.59 MSMP SpeechLoudness ratings (long-term v
40、alues) (x) (x) (x) x (x) (x) x Loudness ratings (short-term values) (x) x Frequency responses (long-term values) (x) (x) (x) x (x) (x) x Frequency responses (short-term values) (x) x Listener sidetone/ talker sidetone (long-term values) (x) (x) (x) (x) x (x) (x) x Harmonic distortion (x) Distortion
41、(x) (x) (x) (x) (x) Out-of-band signals (x) 4 Rec. ITU-T P.501 (01/2012) Non-linear and/or time-variant systems (e.g., mobile phones) Sine wave (Note 1) Noise (Note 2) CSS (Note 3)Probetone SSGITU-T P.50 ITU-T P.59 MSMP SpeechLevel measurements (x) (x) (x) x (x) (x) x Delay measurements (x) (x) x x
42、Echo measurements (x) (x) (x) (x) (x) (x) (x) x Applicable (x) Applicable with some caution NOTE 1 Including modulated sine wave and Fourier spectra. NOTE 2 Including pink, white and switched noise as well as MTF. NOTE 3 Including various combinations of voiced sound and measurement signals (PN-sequ
43、ence, sine, etc.). NOTE 4 Long-term values correspond to steady state behaviour of systems. Short-term values correspond to dynamic behaviour of systems. Hands-free telephones Sine wave (Note 1) Noise (Note 2) CSS (Note 3) Probetone SSG ITU-TP.50 ITU-T P.59 MSMP Speech Loudness ratings (long-term va
44、lues) x x (x) x x x x x Loudness ratings (short-term values) (x) x Frequency responses (long-term values) x x (x) x x x x x Frequency responses (short-term values) (x) x Harmonic distortion x Distortion (x) x Out-of-band signals x Level measurements x x (x) x x x x x Delay measurements x x x x Rec.
45、ITU-T P.501 (01/2012) 5 Hands-free telephones Sine wave (Note 1) Noise (Note 2) CSS (Note 3) Probetone SSG ITU-TP.50 ITU-T P.59 MSMP Speech Switching characteristics (x) (x) x (x) (x) (x) (x) x Reverberation measurements x x Echo path characteristics (x) (x) (x) (x) (x) (x) x Applicable (x) Applicab
46、le with some caution NOTE 1 Including modulated sine wave and Fourier spectra. NOTE 2 Including pink, white and switched noise as well as modulated noise (MTF). NOTE 3 Including various combinations of voiced sound and measurement signals (PN-sequence, sine, etc.). NOTE 4 Long-term values correspond
47、 to steady state behaviour of systems. Short-term values correspond to dynamic behaviour of systems. Echo cancellers Sine wave (Note 1) Noise (Note 2) CSS (Note 3)Probe tone SSGITU-TP.50 ITU-T P.59 MSMP SpeechLevel measurements (x) x (x) x x x x x Delay measurements (x) x x Switching characteristics
48、 (x) (x) x (x) (x) (x) x Background noise performance (x) x (x) x x x x x Echo loss, terminal coupling loss (TCL) (x) (x) (x) x x x x (x) Double-talk performance (x) x (x) (x) (x) x x Applicable (x) Applicable with some caution NOTE 1 Including modulated sine wave and Fourier spectra. NOTE 2 Includi
49、ng pink, white and switched noise as well as modulated noise (MTF). NOTE 3 Including various combinations of voiced sound and measurement signals (PN-sequence, sine, etc.). 6 Rec. ITU-T P.501 (01/2012) 7 Types of test signals Different test signals with different levels of complexity are available and have been evaluated for different types of applications. According to the complexity, different groups of signals can be identified and are listed as follows. 7.1 Non-speech-like (fully artificial) signals
