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 (03/2017) SERIES P: TELEPHONE TRANSMISSION QUALITY, TELEPHONE INSTALLATIONS, LOCAL LINE NETWORKS Voice terminal characteristics Technical requirements and test methods f
2、or the universal wired headset or headphone interface of digital mobile terminals Recommendation ITU-T P.381 ITU-T P-SERIES RECOMMENDATIONS TELEPHONE TRANSMISSION QUALITY, TELEPHONE INSTALLATIONS, LOCAL LINE NETWORKS Vocabulary and effects of transmission parameters on customer opinion of transmissi
3、on quality Series P.10 Voice terminal 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 assessm
4、ent of speech quality Series P.80 Methods 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 M
5、odels and tools for quality assessment 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 vid
6、eo Series P.1500 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T P.381 (03/2017) 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.3
7、81 specifies critical physical and electrical-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
8、 is free to choose either the headset/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 compa
9、tibility between the terminal and the 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 4.0 ITU-T P.381 2017-03
10、-01 12 11.1002/1000/13172 * 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 example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T P.381 (03/2017) FOREWORD The International Telecomm
11、unication Union (ITU) is the United Nations specialized agency in the field of telecommunications, 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 tarif
12、f questions and issuing Recommendations on them with a view to standardizing telecommunications 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 Recommen
13、dations 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 purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommenda
14、tion, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperabili
15、ty 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“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compli
16、ance 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 involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity o
17、r 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 Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required t
18、o 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 http:/www.itu.int/ITU-T/ipr/. ITU 2017 All rights reserved. No part of this publication may be reproduced, by
19、 any means whatsoever, without the prior written permission of ITU. Rec. ITU-T P.381 (03/2017) 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
20、 Physical characteristics . 5 6.1 General rules . 5 6.2 Pin assignments 5 7 Electrical interface specification . 7 7.1 Communication mode 7 7.2 Multimedia playback mode 28 8 Headset specification 32 8.1 Communication mode 32 8.2 Multimedia playback mode 38 9 Function requirements for terminals with
21、the universal headset interface . 41 Appendix I Audio connectivity for sockets with four contact points . 44 I.1 2.5 mm diameter plug connector with four poles . 44 I.2 2.5 mm diameter socket connector with four contact points 45 I.3 3.5 mm diameter plug connector with four poles . 45 I.4 3.5 mm dia
22、meter socket connector with four contact points 46 Appendix II Audio connectivity for sockets with four contact points (optional dimensions to accommodate terminal designs with curved edges) 48 Appendix III Audio connectivity for sockets with three contact points . 49 III.1 2.5 mm diameter plug conn
23、ector with three poles . 49 III.2 2.5 mm diameter socket connector with three contact points 49 III.3 3.5 mm diameter plug connector with three poles . 50 III.4 3.5 mm diameter socket connector with three contact points 50 Appendix IV Other considerations . 52 IV.1 Filter recommendation 52 IV.2 Elec
24、trostatic discharge 52 IV.3 Microphone basics background . 52 IV.4 Vcc voltage for microphone bias 52 IV.5 DC resistance of microphone . 53 Bibliography. 54 Rec. ITU-T P.381 (03/2017) 1 Recommendation ITU-T P.381 Technical requirements and test methods for the universal wired headset or headphone in
25、terface of digital mobile terminals 1 Scope This Recommendation specifies electrical requirements 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 te
26、rminal and the wired analogue headset/headphone, and to have a better user experience. 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
27、or her favourite type of headset or headphone that is available on the market. In the long 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
28、 manufacturers and encourage them to adopt the universal headset interface, the mechanical 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
29、 to this Recommendation. This Recommendation is not applicable for terminals designed solely 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 Recommendati
30、on. At the time of publication, the editions 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 li
31、sted below. A list of the currently valid 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
32、stability and talker echo in international connections. ITU-T P.10 Recommendation ITU-T 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 s
33、peech level. ITU-T P.57 Recommendation ITU-T P.57 (2011), Artificial ears. ITU-T P.58 Recommendation 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
34、 (2000), Transmission characteristics and speech quality parameters of hands-free terminals. 2 Rec. ITU-T P.381 (03/2017) 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. I
35、TU-T P.502 Recommendation ITU-T P.502 (2000), Objective test methods for speech communication 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
36、(2011), Perceptual objective listening quality assessment. ITU-T P.863.1 Recommendation ITU-T P.863.1 (2014), Application guide for Recommendation ITU-T P.863. EN 50332-1 CENELEC EN 50332-1 (2013), Sound system equipment: Headphones and earphones associated with personal music players Maximum sound
37、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 with personal music players Maximum sound pressure level measurement methodology Part 2: Matching of sets with
38、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 manufacturers or different design. ETSI TS 103 106 ETSI TS 103 106 V1.2.1 (2013), Speech and multimedia Transmissi
39、on 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), Sound system equipment Part1: General. IEC 60268-7 IEC 60268-7 (2010), Sound system equipment Part 7: Headphone
40、s 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 Sound level meters Part 1: Specifications. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the
41、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 point located at the end of the ear canal, corresponding to the eardrum position. 3.1.3 earphone IEC 60268-7: Elect
42、roacoustic transducer by which acoustic oscillations are obtained from electric signals and intended to be closely coupled acoustically to the ear. Rec. ITU-T P.381 (03/2017) 3 3.1.4 headset ITU-T P.10: A device which includes a telephone receiver and transmitter which is typically secured to the he
43、ad or the ear of the wearer. 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 Figure 1 of ITU-T P.64). 3.2 Terms defined in this Recommendation This Recommendation defines the following terms:
44、 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 that of the average adult ear over a given frequency band (based on the definition in ITU-T P.10). 3.2.2 codec: Comb
45、ination 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) for telephonometry: A manikin that extends downwards from the top of the head to the waist. It is designed to simu
46、late 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 definition in ITU-T P.10). 3.2.4 headphone: An object based on the assembly of one or two earphones on a headband or chinb
47、and, 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): The score is calculated by means of an objective model which aims at predicting the quality for a listening-only te
48、st 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 from the measurement system to the device under test (DUT). 3.2.7 send: The sending direction of the signal tran
49、smission, 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 Breakthrough 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 t
