1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T P.501 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2017) SERIES P: TELEPHONE TRANSMISSION QUALITY, TELEPHONE INSTALLATIONS, LOCAL LINE NETWORKS Objective measuring apparatus Test signals for use in telephonometry Rec
2、ommendation ITU-T P.501 ITU-T P-SERIES RECOMMENDATIONS TELEPHONE TRANSMISSION QUALITY, TELEPHONE INSTALLATIONS, LOCAL LINE NETWORKS Vocabulary and effects of transmission parameters on customer opinion of transmission quality Series P.10 Voice terminal characteristics Series P.30 P.300 Reference sys
3、tems Series P.40 Objective measuring apparatus Series P.50 P.500 Objective 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 Methods for objective and subjective assessment of
4、speech and video quality Series P.800 Audiovisual quality in multimedia services Series P.900 Transmission performance and QoS aspects of IP end-points Series P.1000 Communications involving vehicles Series P.1100 Models and tools for quality assessment of streamed media Series P.1200 Telemeeting as
5、sessment Series P.1300 Statistical analysis, evaluation and reporting guidelines of quality measurements Series P.1400 Methods for objective and subjective assessment of quality of services other than speech and video Series P.1500 For further details, please refer to the list of ITU-T Recommendatio
6、ns. Rec. ITU-T P.501 (03/2017) i Recommendation ITU-T P.501 Test signals for use in telephonometry Summary Recommendation ITU-T P.501 describes test signals that are applicable for several purposes in telephonometry. Recommendation ITU-T P.501 gives a wide variety of test signals starting with low c
7、omplexity test signals up to test signals with a high degree of complexity incorporating many typical parameters of speech. Besides technical signals, such as sine waves or noise, more speech-like signals are described. Recommendation ITU-T P.501 describes the principles of signal construction for e
8、ach type of test signal. Characteristic properties, such as power density spectra, probability density functions or shaping filter responses, are shown. Recommendation ITU-T P.501 gives an overview of the typical application of the test signals described. This overview is a guideline giving general
9、application rules. The detailed description of the application, however, should be found in the individual Recommendations describing the measurement procedures for specific applications. In order to avoid problems in creating the test signals described, all these test signals are freely available f
10、or download from the ITU-T test signals database. Annex A proposes two test signals a pseudo noise sequence (PN-sequence) with a low crest factor and a logarithmically distributed multi-sine wave for the measurement of terminal coupling loss (TCL). Annex B provides speech files and noise sequences t
11、o be used in combination with objective speech quality evaluation methods. This speech material does not replace the speech material found in Supplement 23 to the ITU-T P-series Recommendations. Appendix I provides a description of the processing applied to the speech signals in clause 7.3. This Rec
12、ommendation includes an electronic attachment containing the set of freely available test signals described in the Recommendation. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T P.501 1996-08-30 12 11.1002/1000/3635 2.0 ITU-T P.501 2000-05-18 12 11.1002/1000/5080 2.1 ITU-T
13、P.501 (2000) Amd. 1 2004-05-14 12 11.1002/1000/7411 3.0 ITU-T P.501 2007-06-29 12 11.1002/1000/9065 4.0 ITU-T P.501 2009-12-14 12 11.1002/1000/10657 5.0 ITU-T P.501 2012-01-13 12 11.1002/1000/11459 5.1 ITU-T P.501 (2012) Amd. 1 2012-07-14 12 11.1002/1000/11686 5.2 ITU-T P.501 (2012) Amd. 2 2014-10-2
14、9 12 11.1002/1000/12330 5.3 ITU-T P.501 (2012) Amd. 3 2015-06-29 12 11.1002/1000/12515 6.0 ITU-T P.501 2017-03-01 12 11.1002/1000/13173 _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For exampl
15、e, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T P.501 (03/2017) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardizat
16、ion 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 Assembly (WTSA), which mee
17、ts 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 which fall within ITU-Ts
18、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 this Recommendation is
19、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 language such as “must“ a
20、nd 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 RIGHTSITU draws attention to the possibility that the practice or implementation of this Recommendation may inv
21、olve 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 of approval of this Rec
22、ommendation, 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 TSB patent database at h
23、ttp:/www.itu.int/ITU-T/ipr/. ITU 2017 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 (03/2017) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 2 3.1 Terms defined elsewhe
24、re 2 3.2 Terms defined in this Recommendation . 2 4 Abbreviations and acronyms 2 5 Conventions 3 6 Overview of test signals and typical applications . 3 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 34 7.4 Additional languag
25、es 44 Annex A Test signals for terminal coupling loss tests 51 Annex B Speech files and noise sequences 52 B.1 General . 52 B.2 Description of the recording procedure used for speech signals 52 B.3 Test sentences . 52 B.4 Noise sequences 57 Annex C Speech files prepared for use with ITU-T P.800 conf
26、ormant applications and perceptual-based objective speech quality prediction 60 C.1 General . 60 C.2 Test sentences . 60 Annex D Speech files composed of a pair of sentences spoken by a male and a female speaker 65 D.1 General . 65 D.2 Test sentences . 66 Appendix I Description of the processing app
27、lied to the speech signals in clause 7.3 . 68 I.1 Filter for DC removal . 68 I.2 Creation of the single-talk speech sequence . 68 I.3 Example high-pass filter designs 68 Bibliography. 70 Electronic attachment: Set of freely available test signals described within the Recommendation.Rec. ITU-T P.501
28、(03/2017) 1 Recommendation ITU-T P.501 Test signals for use in telephonometry 1 Scope This Recommendation1 describes test signals that are applicable for several purposes in telephonometry. A wide variety of test signals is given, starting with low complexity test signals up to test signals with a h
29、igh degree of complexity incorporating many typical parameters of speech. Besides technical signals, such as sine waves or noise, more speech-like signals are described. The overview of typical applications of the test signals described is a guideline giving general application rules. The detailed d
30、escription of the application, however, should be found in individual Recommendations describing the measurement procedures for specific applications. To avoid difficulties when creating the test signals described, all these signals are freely available for download from the ITU-T test signals datab
31、ase: http:/www.itu.int/net/itu-t/sigdb/genaudio/Pseries.htm. 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 editions indicated were valid. Al
32、l 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 ITU-T Recommendations is re
33、gularly 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 international connections. ITU-T G.168 R
34、ecommendation ITU-T G.168 (2015), 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.56 (2011), Objective measure
35、ment 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 characteristics and speech quality
36、parameters of hands-free terminals. ITU-T P.800 Recommendation ITU-T P.800 (1996), Methods for subjective determination of transmission quality. ITU-T P.830 Recommendation ITU-T P.830 (1996), Subjective performance assessment of telephone-band and wideband digital codecs. _ 1 This Recommendation inc
37、ludes an electronic attachment containing the set of freely-available test signals described within the Recommendation. 2 Rec. ITU-T P.501 (03/2017) ITU-T P.862 Recommendation ITU-T P.862 (2001), Perceptual evaluation of speech quality (PESQ): An objective method for end-to-end speech quality assess
38、ment of narrow-band telephone networks and speech codecs. ITU-T P.862.3 Recommendation ITU-T P.862.3 (2007), Application guide for objective quality measurement based on Recommendations ITU-T P.862, ITU-T P.862.1 and ITU-T P.862.2. ITU-T P.863 Recommendation ITU-T P.863 (2014), Perceptual objective
39、listening quality assessment. ITU-T P.863.1 Recommendation ITU-T P.863.1 (2014), Application guide for Recommendation ITU-T P.863. 3 Definitions 3.1 Terms defined elsewhere None. 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: 3.2.1 crest factor: Peak-to-RMS
40、 (root mean square) 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 speech-like signal, taking into account the generat
41、ion 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 Fourier transformation of a predefined frequency spec
42、trum. 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, especially in reverberant conditions, derived from measurin
43、g the modulation transfer function. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: CSS Composite Source Signal DC Direct Current FFT Fast Fourier Transform FIR Finite Impulse Response IIR Infinite Impulse Response LTI Linear Time-Invariant HVAC Heatin
44、g, Ventilation and Air Conditioning mc Markov chain Rec. ITU-T P.501 (03/2017) 3 MRP Mouth Reference Point MSMP Markov Speech Model Process MTF Modulation Transfer Function PCM Pulse Code Modulation PDF Probability Density Function PN Pseudo Noise RCV Receive RMS Root Mean Square SND Send SSG Simula
45、ted Speech Generator STI Speech Transmission Index TCL Terminal Coupling Loss 5 Conventions None. 6 Overview of test signals and typical applications See Tables 6-1 to 6-5. Table 6-1 Linear, time-invariant systems (e.g., standard handset telephones without echo/noise cancelling) Sine wave (Note 1) N
46、oise (Note 2) CSS (Note 3) Probe tone SSG ITU-T P.50 ITU-T P.59 MSMP Speech Loudness ratings Frequency responses Listener sidetone/ talker sidetone Harmonic distortion Distortion Out-of-band signals Level measurements Delay measurements () () Echo measurements () () () () () Applicable () Applicable
47、 with some caution NOTE 1 Including modulated sine wave and Fourier spectra. NOTE 2 Including pink, white and switched noise. NOTE 3 Including various combinations of voiced sound and measurement signals (PN-sequence, sine, etc.). 4 Rec. ITU-T P.501 (03/2017) Table 6-2 Non-linear and/or time-variant
48、 systems (e.g., mobile phones) Sine wave (Note 1) Noise (Note 2) CSS (Note 3) Probe tone SSG ITU-T P.50 ITU-T P.59 MSMP Speech Loudness ratings (long-term values) () () () () () Loudness ratings (short-term values) () Frequency responses (long-term values) () () () () () Frequency responses (short-term values) () Listener sidetone/ talker sidetone (long-term values) () () () () () () Harmonic distortion () Distortion () () () () () Out-of-band signals () Level measurements () () () () () Delay measurements () () Echo measurements () () () () () () () Applicable () Applicable with so
