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.381 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (07/2016) SERIES P: TERMINALS AND SUBJECTIVE AND OBJECTIVE ASSESSMENT METHODS Voice terminal characteristics Technical requirements and test methods for the universal wi
2、red headset or headphone interface of digital mobile terminals Recommendation ITU-T P.381 ITU-T P-SERIES RECOMMENDATIONS TERMINALS AND SUBJECTIVE AND OBJECTIVE ASSESSMENT METHODS Vocabulary and effects of transmission parameters on customer opinion of transmission quality Series P.10 Voice terminal
3、characteristics Series P.30 P.300 Reference systems 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 Meth
4、ods for objective and subjective assessment of 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
5、 of streamed media Series P.1200 Telemeeting assessment 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,
6、please refer to the list of ITU-T Recommendations. Rec. ITU-T P.381 (07/2016) i Recommendation ITU-T P.381 Technical requirements and test methods for the universal wired headset or headphone interface of digital mobile terminals Summary Recommendation ITU-T P.381 specifies critical physical and ele
7、ctrical-acoustical characteristics for the universal headset interface and provides corresponding test methods. Both 3.5 mm and 2.5 mm diameter headset/headphone interfaces have been widely used in digital mobile terminals in recent years. Nowadays, the consumer is free to choose either the headset/
8、headphone originally provided by the terminal manufacturer or others that are offered separately. However, the quality of service (QoS)/quality of experience (QoE) perceived by users is influenced by both the electrical performance of the interface and the compatibility between the terminal and the
9、connected headset/headphone. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T P.381 2012-08-22 12 11.1002/1000/11685 2.0 ITU-T P.381 2014-02-13 12 11.1002/1000/12139 3.0 ITU-T P.381 2016-07-29 12 11.1002/1000/12970 * To access the Recommendation, type the URL http:/handle.itu
10、.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T P.381 (07/2016) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecomm
11、unications, information and communication technologies (ICTs). The ITU Telecommunication 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 telecommun
12、ications on a worldwide basis. The World Telecommunication Standardization Assembly (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 proced
13、ure laid down in WTSA Resolution 1. In some areas of information technology which 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 teleco
14、mmunication administration and a recognized operating agency. Compliance with this 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 the
15、se mandatory provisions are met. The words “shall“ or some other obligatory language 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 RIGHTSITU
16、draws attention to the possibility that the practice or implementation of this 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 member
17、s or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not
18、represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2016 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.381 (0
19、7/2016) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 2 3.1 Terms defined elsewhere 2 3.2 Terms defined in this Recommendation . 3 4 Abbreviations and acronyms 3 5 General description . 5 6 Physical characteristics . 5 6.1 General rules . 5 6.2 Pin assignments 5 7 Electrical
20、interface specification . 7 7.1 Communication mode 7 7.2 Multimedia playback mode 26 8 Headset specification 30 8.1 Communication mode 30 8.2 Multimedia playback mode 35 9 Function requirements for terminals with the universal headset interface . 38 Appendix I Audio connectivity for sockets with fou
21、r contact points . 41 I.1 2.5 mm diameter plug connector with four poles . 41 I.2 2.5 mm diameter socket connector with four contact points 42 I.3 3.5 mm diameter plug connector with four poles . 42 I.4 3.5 mm diameter socket connector with four contact points 43 Appendix II Audio connectivity for s
22、ockets with four contact points (optional dimensions to accommodate terminal designs with curved edges) 45 Appendix III Audio connectivity for sockets with three contact points . 46 III.1 2.5 mm diameter plug connector with three poles . 46 III.2 2.5 mm diameter socket connector with three contact p
23、oints 46 III.3 3.5 mm diameter plug connector with three poles . 47 III.4 3.5 mm diameter socket connector with three contact points 47 Appendix IV Other considerations . 49 IV.1 Filter recommendation 49 IV.2 Electrostatic discharge 49 IV.3 Microphone basics background . 49 IV.4 Vcc voltage for micr
24、ophone bias 49 IV.5 DC resistance of microphone . 50 Bibliography. 51 Rec. ITU-T P.381 (07/2016) 1 Recommendation ITU-T P.381 Technical requirements and test methods for the universal wired headset or headphone interface of digital mobile terminals 1 Scope This Recommendation specifies electrical re
25、quirements and test methods for the universal analogue headset/headphone interface used in digital mobile terminals. The principle of this document is to ensure adequate compatibility between the digital mobile terminal and the wired analogue headset/headphone, and to have a better user experience.
26、The universality of the headset/headphone interface will facilitate the separation of sales between digital mobile terminals and headsets/headphones. One of the benefits is that the user can be free to choose his or her favourite type of headset or headphone that is available on the market. In the l
27、ong run, it will reduce e-waste. Furthermore, the universal interface can be used as the electric coupling design in hands-free systems and hearing aids for wider harmonization. In order to provide instructions to manufacturers and encourage them to adopt the universal headset interface, the mechani
28、cal dimensions are shown in Appendices I, II and III. This Recommendation is applicable to digital mobile terminals with a physical analogue audio output/input interface. Other similar ICT equipment may also refer to this Recommendation. This Recommendation is not applicable for terminals designed s
29、olely for digital headset/headphone usage. 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. All Recommendations
30、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 regularly published.
31、 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 P.10 Recommendation ITU-T
32、 P.10/G.100 (2006), Vocabulary for performance and quality of service. ITU-T P.50 Recommendation ITU-T P.50 (1999), Artificial voices. ITU-T P.56 Recommendation ITU-T P.56 (2011), Objective measurement of active speech level. ITU-T P.57 Recommendation ITU-T P.57 (2011), Artificial ears. ITU-T P.58 R
33、ecommendation ITU-T P.58 (2011), Head and torso simulator for telephonometry. 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 parameters of hands-free termi
34、nals. 2 Rec. ITU-T P.381 (07/2016) ITU-T P.380 Recommendation ITU-T P.380 (2003), Electro-acoustic measurements on headsets. ITU-T P.501 Recommendation ITU-T P.501 (2009), Test signals for use in telephonometry. ITU-T P.502 Recommendation ITU-T P.502 (2000), Objective test methods for speech communi
35、cation systems using complex test signals. ITU-T P.581 Recommendation ITU-T P.581 (2009), Use of head and torso simulator (HATS) for hands-free and handset terminal testing. ITU-T P.863 Recommendation ITU-T P.863 (2011), Perceptual objective listening quality assessment. EN 50332-1 CENELEC EN 50332-
36、1 (2013), Sound system equipment: Headphones and earphones associated with personal music players Maximum sound pressure level measurement methodology Part 1: General method for “one package equipment“. EN 50332-2 CENELEC EN 50332-2 (2013), Sound system equipment: Headphones and earphones associated
37、 with personal music players Maximum sound pressure level measurement methodology Part 2: Matching of sets with headphones if either or both are offered separately, or are offered as one package equipment but with standardised connectors between the two allowing to combine components of different ma
38、nufacturers or different design. ETSI TS 103 106 ETSI TS 103 106 V1.2.1 (2013), Speech and multimedia Transmission Quality (STQ); Speech quality performance in the presence of background noise: Background noise transmission for mobile terminals-objective test methods. IEC 60268-1 IEC 60268-1 (1985),
39、 Sound system equipment Part1: General. IEC 60268-7 IEC 60268-7 (2010), Sound system equipment Part 7: Headphones and earphones. IEC 61260-1 IEC 61260 -1(2014), Electroacoustics Octave-band and fractional-octave-band filters. Part 1: Specifications. IEC 61672-1 IEC 61672-1 (2013), Electroacoustics S
40、ound level meters Part 1: Specifications. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 composite source signal (CSS) ITU-T P.10: Signal composed in time by various signal elements. 3.1.2 eardrum reference point (DRP) ITU-T P.10: A po
41、int located at the end of the ear canal, corresponding to the eardrum position. 3.1.3 earphone IEC 60268-7: Electroacoustic transducer by which acoustic oscillations are obtained from electric signals and intended to be closely coupled acoustically to the ear. 3.1.4 headset ITU-T P.10: A device whic
42、h includes a telephone receiver and transmitter which is typically secured to the head or the ear of the wearer. Rec. ITU-T P.381 (07/2016) 3 3.1.5 mouth reference point (MRP) ITU-T P.10: Point 25 mm in front of and on the axis of the lip plane of the artificial mouth or a typical human mouth (see F
43、igure 1 of ITU-T P.64). 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: 3.2.1 artificial ear: A device which incorporates an acoustic coupler and a calibrated microphone for measuring sound pressure, and which has an overall acoustic impedance similar to tha
44、t of the average adult ear over a given frequency band (based on the definition in ITU-T P.10). 3.2.2 codec: Combination of an analogue-to-digital encoder and a digital-to-analogue decoder operating in opposite directions of transmission in the same equipment. 3.2.3 head and torso simulator (HATS) f
45、or telephonometry: A manikin that extends downwards from the top of the head to the waist. It is designed to simulate the sound pick-up characteristics and the acoustic diffraction produced by the average adult, and to reproduce the acoustic field generated by the human mouth (based on the definitio
46、n in ITU-T P.10). 3.2.4 headphone: An object based on the assembly of one or two earphones on a headband or chinband, the use of which may be optional (e.g., with intra-concha earphones) (based on the definition in IEC 60268-7). 3.2.5 mean opinion score listening-only quality objective (MOS-LQO): Th
47、e score is calculated by means of an objective model which aims at predicting the quality for a listening-only test situation. Objective measurements made using the model given in ITU-T P.863 give results in terms of MOS-LQO. 3.2.6 receive: The receiving direction of the signal transmission, usually
48、 from the measurement system to the device under test (DUT). 3.2.7 send: The sending direction of the signal transmission, usually from the device under test (DUT) to the measurement system. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: ABT Audio Bre
49、akthrough Testing AGC Automatic Gain Control AH,R,dt Attenuation range in the receive direction during double talk AH,S,dt Attenuation range in the send direction during double talk dBFS decibels relative to Full Scale. dBV decibels relative to 1 Volt dBVp decibels relative to 1 Volt, psophometrically weighted DRP Drum Reference Position DUT Device Under Test EC Echo Canceller ECM Electret condenser microphone EL Echo Loss EMI Electromagnetic Interference ESD E
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