1、 ETSI ES 200 381-1 V1.2.1 (2012-10) Telephony for hearing impaired people; Inductive coupling of telephone earphones to hearing aids; Part 1: Fixed-line speech terminals ETSI Standard ETSI ETSI ES 200 381-1 V1.2.1 (2012-10)2Reference RES/STQ-196 Keywords coupling, hearing aid, inductive, telephony E
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4、erence shall be the printing on ETSI printers of the PDF version kept on a specific network drive within ETSI Secretariat. Users of the present document should be aware that the document may be subject to revision or change of status. Information on the current status of this and other ETSI document
5、s is available at http:/portal.etsi.org/tb/status/status.asp If you find errors in the present document, please send your comment to one of the following services: http:/portal.etsi.org/chaircor/ETSI_support.asp Copyright Notification No part may be reproduced except as authorized by written permiss
6、ion. The copyright and the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute 2012. All rights reserved. DECTTM, PLUGTESTSTM, UMTSTMand the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members. 3GPPTM and LTE are Trade Ma
7、rks of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. GSM and the GSM logo are Trade Marks registered and owned by the GSM Association. ETSI ETSI ES 200 381-1 V1.2.1 (2012-10)3Contents Intellectual Property Rights 4g3Foreword . 4g31 Scope 5g32 References 5g32
8、.1 Normative references . 5g32.2 Informative references 6g33 Definitions and abbreviations . 6g33.1 Definitions 6g33.2 Abbreviations . 7g34 Introduction 7g34.1 General . 7g34.2 Background 7g35 Requirements 8g35.1 Introduction 8g35.2 Magnetic field strength level 8g35.3 Linearity of the magnetic fiel
9、d strength . 8g35.4 Frequency characteristics . 9g35.5 Distortion 9g35.6 Signal to Noise ratio . 9g36 The probe coil . 10g36.1 Dimensions . 10g36.2 Calibration of probe coil . 11g36.3 Distortion 11g36.4 Connecting leads for probe coil 11g37 Test procedures 11g37.1 Calibration of receive sound pressu
10、re level 12g37.2 Measurement of the magnetic field strength level 12g37.3 Measurement of the linearity of the magnetic field strength 12g37.4 Measurement of frequency characteristics . 12g37.5 Measurement of distortion 12g37.6 Measurement of signal to noise ratio 12g3Annex A (normative): Packaging,
11、labelling and user instructions 13g3A.1 Packaging and labelling 13g3A.2 User instructions . 13g3Annex B (informative): Step-by-step measurement procedures 14g3Annex C (informative): Symbol indicating facilities for the hearing impaired 15g3Annex D (normative): Calibration of the probe coil . 16g3Ann
12、ex E (informative): Components of the inductive field 17g3Annex F (informative): Bibliography . 18g3History 19g3ETSI ETSI ES 200 381-1 V1.2.1 (2012-10)4Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertain
13、ing to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretari
14、at. Latest updates are available on the ETSI Web server (http:/ipr.etsi.org). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the
15、ETSI Web server) which are, or may be, or may become, essential to the present document. Foreword This ETSI Standard (ES) has been produced by ETSI Technical Committee Speech and multimedia Transmission Quality (STQ). NOTE: The present document prepare materials for a future update of ETS 300 381 3
16、published in December 1994. The update of ETS 300 381 3 may be updated into an EN, taking into account the contents of the present document. Several administrations and operating agencies have expressed the opinion that it would be acceptable if the present document were to be made mandatory for pub
17、lic telephones and wherever telephones are installed on the basis of safety, e.g. in lifts. It would not be expected to be mandatory in all countries for all telephone terminals. However, if such a facility is made available, it should conform to the requirements of the present document, and labels
18、and literature advertising the facility should not be related to a particular product unless it does in fact so comply. Annexes A and D of the present document are normative while annexes B, C, E and F are informative. The present document aims at enlarging the scope of the speech terminals, as the
19、initial document only dealt with PSTN and ISDN speech terminals, and to update the measurement methods that have been changed, in particular with the use of HATS. In addition, some quality parameters have been provided. The present document is part 1 of a multi-part deliverable covering telephony fo
20、r hearing impaired people; inductive coupling of telephone earphones to hearing aids, as identified below: Part 1: “Fixed-line speech terminals“; Part 2: “Cellular speech terminals“. Part 1 provides general principles and testing methods for inductive coupling with telephone earphones. It also defin
21、es the requirements for wired telephone earphones and the dedicated test methods. Part 2 defines the requirements for cellular telephone earphones and the dedicated test methods. ETSI ETSI ES 200 381-1 V1.2.1 (2012-10)51 Scope The present document applies to fixed-line telephones having earphones (s
22、ee ITU-T Recommendation P.57 4) which are intended for direct application to the ear (e.g. handsets, supra-aural headsets) and which are intended to provide, through the earphone, a magnetic field for coupling to hearing aids. It specifies the level linearity and frequency dependence of the magnetic
23、 field strength produced by the handset and characteristics for the calibrated probe coil. It also specifies provisions for distortion, noise and signal to noise ratio of the magnetic field. Provisions for DECT terminals, are within the scope of this part 1 of this multipart deliverable, even if it
24、is a cordless technology. Handsfree or loudspeaking devices are outside the scope of the present document. The requirements for inductive coupling with wireless terminal earphones are outside the scope of the present document. 2 References References are either specific (identified by date of public
25、ation and/or edition number or version number) or non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the reference document (including any amendments) applies. Referenced documents which are not found to be publicly available in
26、the expected location might be found at http:/docbox.etsi.org/Reference. NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee their long term validity. 2.1 Normative references The following referenced documents are necessary for the applica
27、tion of the present document. 1 ITU-T Recommendation P.370: “Coupling hearing aids to telephone sets“. 2 ITU-T Recommendation P.64: “Determination of sensitivity/frequency characteristics of local telephone systems“. 3 ETSI ETS 300 381: “Telephony for hearing impaired people;Inductive coupling of te
28、lephone earphones to hearing aids“. 4 ITU-T Recommendation P.57: “Artificial ears“. 5 ETSI ETS 300 488: “Terminal Equipment (TE); Telephony for hearing impaired people; Characteristics of telephone sets that provide additional receiving amplification for the benefit of the hearing impaired“. 6 ETSI
29、ETS 300 679: “Terminal Equipment (TE); Telephony for the hearing impaired; Electrical coupling of telephone sets to hearing aids“. 7 ITU-T Recommendation P.58: “Head and torso simulator for telephonometry“. 8 ETSI ES 203 038: “Speech and multimedia Transmission Quality (STQ); Requirements and tests
30、methods for terminal equipment incorporating a handset when connected to the analogue interface of the PSTN“. 9 ETSI ES 202 737: “Speech and multimedia Transmission Quality (STQ); Transmission requirements for narrowband VoIP terminals (handset and headset) from a QoS perspective as perceived by the
31、 user“. ETSI ETSI ES 200 381-1 V1.2.1 (2012-10)610 ETSI ES 202 739: “Speech and multimediaTransmission Quality (STQ); Transmission requirements for wideband VoIP terminals (handset and headset) from a QoS perspective as perceived by the user“. 11 ETSI EN 300 176-2: “Digital Enhanced Cordless Telecom
32、munications (DECT); Test specification; Part 2: Audio and speech“. 12 ETSI EN 300 175-8: “Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); Part 8: Speech and audio coding and transmission“. 13 ETSI I-ETS 300 245-2: “Integrated Services Digital Network (ISDN);Technical char
33、acteristics of telephony terminals; Part 2: PCM A-law handset telephony“. 14 ETSI I-ETS 300 245-5: “Integrated Services Digital Network (ISDN);Technical characteristics of telephony terminals; Part 5: Wideband (7 kHz) handset telephony“. 15 ITU-T Recommendation P.501: “Test signals for use in teleph
34、onometry“. 16 ITU-T Recommendation P.581: “Use of head and torso simulator (HATS) for hands-free and handset terminal testing“. 17 ANSI C63.19-2011: “American National Standard Methods of Measurement of Compatibility between Wireless Communication Devices and Hearing Aids“. 18 IEC 60118-13: “Hearing
35、 aids- Electromagnetic compatibility“. 19 IEC 60118-1: “Methods of measurement of electroacoustic characteristics of hearing aids; Part 1: Hearing aids with induction pick-up coil input“. 20 IEC 60118-4: “Methods of measurement of electroacoustic characteristics of hearing aids; Part 4: Magnetic fie
36、ld strength in audio-frequency induction loops for hearing aid purposes“. 2.2 Informative references The following referenced documents are not necessary for the application of the present document but they assist the user with regard to a particular subject area. Not applicable. 3 Definitions and a
37、bbreviations 3.1 Definitions For the purposes of the present document, the following terms and definitions apply: Composite Source Signal (CSS): signal composed in time by various signal elements (ITU-T Recommendation P.501 15) level of magnetic field strength: value of the magnetic field strength e
38、xpressed in Amperes per metre (A/m) permissible range: range into which the measured level of the magnetic field strength needs to fall to comply with the present document plane of measurement: plane parallel to the earcap plane at a distance of 10 mm preferred range: range of magnetic field strengt
39、h likely to be required for satisfactory performance by hearing aids designed primarily for coupling to magnetic loops often installed in auditoria sound pressure level: acoustic sound pressure level is expressed in decibels relative to 1 Pascal (or dBPa) ETSI ETSI ES 200 381-1 V1.2.1 (2012-10)73.2
40、Abbreviations For the purposes of the present document, the following abbreviations apply: CSS Composite Source Signal DECT Digital Enhanced Cordless Telecommunications DRP Ear-Drum Reference Point HATS Head And Torso Simulator ISDN Integrated Services Digital Network PSTN Public Switched Telephone
41、Network THD Total Harmonic Distortion VoIP Voice over Internet Protocol 4 Introduction 4.1 General It is recognised that there is a sizeable proportion of telephone users that have difficulty in conversing over a telephone connection due to hearing loss. To alleviate these difficulties special means
42、 have been provided in many national systems to enable hearing impaired users to couple their hearing aids inductively to the telephone receiver, and a number of national/international specifications define characteristics for this form of coupling. The present document addresses the requirements fo
43、r successful inductive coupling of hearing aids to telephone sets. Furthermore, it is also recognised that many hearing impaired users are able to have satisfactory telephone conversations while coupling their hearing aids acoustically to the telephone receiver, or even using the telephone handset w
44、ithout a hearing aid. This latter situation is possible due to the fact that, under good conditions, a telephone connection can be louder than a face-to-face conversation over a 1 metre air path by up to 30 dB. The inclusion of inductive coupling does not reduce or replace existing technical standar
45、ds that apply to a handset. Inductive coupling can be combined with other additional functionality, such as amplification or extra earpieces, provided specifically for people with special needs. Provision of additional amplification in the mouth-to-ear path can greatly increase the proportion of tel
46、ephone conversations involving hearing impaired users that are rated as “good“. Such provision is defined in ETS 300 488 5. Certain national standards also exist to enable direct electrical connection of hearing aids to telephone apparatus, such as defined in ETS 300 679 6. 4.2 Background Magnetic i
47、nduction systems incorporated in telephone handsets generate an alternating magnetic field with special characteristics which make the field detectable by hearing aids equipped with induction pick-up coils. Reception of an audio-frequency signal via an induction pick-up coil can often allow an accep
48、table signal-to-noise ratio to be achieved in cases where the acoustical reception would otherwise be degraded by background noise. The magnetic field strength, which enables induction pick up coils in hearing aids to function effectively, shall be high enough to produce an acceptable signal to nois
49、e ratio but not so high as to cause overloading of the hearing aid. The value of the magnetic field strength given in the present document has been chosen so that these requirements are met as far as possible. Measurement methods used in the present document are in accordance with those given in ITU-T Recommendations P 370 1 and P.64 2. This standard applies, for terminals intended to provide a magnetic field for coupling to hearing aids, in complement with requirements and measurements methods defined in the relevant st