1、BRITISH STANDARD BS6083-9: 1986 IEC118-9: 1985 Incorporating Amendment No.1 Hearing aids Part 9: Methods for measurement of characteristics of hearing aids with bone vibrator output (Implementation of CENELECHD450.9S1) UDC 616.28-76:534.773.08BS6083-9:1986 This British Standard, having been prepared
2、 under the directionof the Electronic Equipment Standards Committee,was published underthe authority of the BoardofBSI and comes intoeffecton 28November1986 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference EEL/24 Draft for comment82/32765 DC ISBN 0 58
3、0 15485 8 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Electronic Equipment Standards Committee (EEL/-) to Technical Committee EEL/24, upon which the following bodies were represented: British Medical Association British Society of Au
4、diology British Telecommunications plc Confederation of British Industry Department of Health and Social Security Department of Trade and Industry (National Physical Laboratory) Health and Safety Executive Hearing Aid Industry Association Institute of Acoustics Institute of Sound and Vibration Resea
5、rch Institution of Electronic and Radio Engineers Medical Research Council National Coal Board National Health Service Royal Aeronautical Society Royal National Institute for the Deaf Society of Hearing Aid Audiologists Limited Amendments issued since publication Amd. No. Date of issue Comments 6186
6、 October1990 Indicated by a sideline in the marginBS6083-9:1986 BSI 10-1999 i Contents Page Committees responsible Inside front cover National foreword ii Introduction 1 1 Scope 1 2 Object 1 3 General 1 4 Explanation of terms 1 5 Test equipment 2 6 Test conditions 3 7 Measurements 4 8 Frequency resp
7、onse recording chart 5 Appendix A Examples of test assemblies 6 Figure A.1 An example of a hearing aid with an integral bone vibrator under test 6 Figure A.2 An example of a bone vibrator with headband mounted on the mechanical coupler 6 Figure A.3 An example of a spectacle hearing aid with an integ
8、ral bone vibrator under test and spectacle arm attached to hinge 7 Figure A.4 An example of a bone vibrator with headband mounted on the mechanical coupler and amplifier with microphone permanently attached to the headband 7 Publications referred to Inside back coverBS6083-9:1986 ii BSI 10-1999 Nati
9、onal foreword This Part of BS6083 has been prepared under the direction of the Electronic Equipment Standards Committee and is identical with IEC Publication118-9:1985 “Hearing aids Part9: Methods of measurement of characteristics of hearing aids with bone vibrator output”, published by the Internat
10、ional Electrotechnical Commission(IEC). This standard is also in agreement with Harmonization Document HD450.9 S1 published by the European Committee for Electrotechnical Standardization (CENELEC). BS 6083 consists of the following Parts: Part 0:1984: Methods for measurement of electroacoustical cha
11、racteristics; Part 1:1984: Method for measurement of characteristics of hearing aids with induction pick-up coil input; Part 2:1984: Methods for measurement of electroacoustical characteristics of hearing aids with automatic gain control circuits; Part 3:1984: Methods for measurement of electroacous
12、tical characteristics of hearing aid equipment not entirely worn on the listener; Part 4:1981: Specification for magnetic field strength in audio-frequency induction loops for hearing aid purposes; Part 5:1984: Specification for dimensions of the nipple and sealing device for insert earphones; Part
13、6:1985: Specification for characteristics of electrical input circuits for hearing aids; Part 7:1985: Methods for measurement of the performance characteristics of hearing aids for quality inspection on delivery; Part 8:1985: Methods for measurement of the performance characteristics of hearing aids
14、 under simulated in situ working conditions; Part 9:1986: Methods for measurement of characteristics of hearing aids with bone vibrator outputs; Part 10: Guide to hearing aid standards; Part 11:1984: Specification for symbols and other markings on hearing aids and related equipment. Terminology and
15、conventions. The text of the International Standard has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards. Textual error. When adopting the text of the International Stand
16、ard, the textual error given below was discovered. It has been marked in the text and hasbeen reported to the IEC in a proposal to amend the text of the InternationalStandard. In the introduction, in line2 of paragraph5, for “(e.g.a headband type bone conduction hearing aid)” read “(e.g.a spectacle
17、type bone conduction hearingaid)”.BS6083-9:1986 BSI 10-1999 iii A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity f
18、rom legal obligations. Cross-references International Standards Corresponding British Standards IEC68 BS2011 Basic environmental testing procedures (Most Parts are identical or technically equivalent to the corresponding IEC Parts) BS6083 Hearing aids IEC118-0:1983 Part0:1984 Methods for measurement
19、 of electroacoustical characteristics (Identical) IEC118-1:1983 Part1:1984 Method for measurement of characteristics of hearing aids with induction pick-up coil input (Identical) IEC118-7:1983 Part7:1985 Methods for measurement of the performance characteristics of hearing aids for quality inspectio
20、n on delivery (Identical) IEC263:1982 BS6397:1983 Specification for scales and sizes for plotting frequency characteristics and polar diagrams (Identical) IEC373:1971 BS4009:1975 Specification for an artificial mastoid for the calibration of bone vibrators used in hearing aids and audiometers (Techn
21、ically equivalent) Summary of pages This document comprises a front cover, an inside front cover, pagesi to iv, pages1to8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment tabl
22、e on the inside front cover.iv blankBS6083-9:1986 BSI 10-1999 1 Introduction IEC Publication118-0: Hearing Aids, Part0:Measurement of Electroacoustical Characteristics, gives information on methods of test for air conduction hearing aids. The majority of hearing aids in use are of this type but a sm
23、all percentage use a bone vibrator instead of an earphone. The use of a bone vibrator requires a different method of measuring the output from the hearing aid and also makes it impractical to measure amplification directly in terms of acoustic gain. Amplification in the case of an air conduction hea
24、ring aid is expressed as the difference between the output sound pressure level in an acoustic coupler or ear simulator and the input sound pressure level measured in a specified manner. However, with bone conduction hearing aids the input is in terms of sound pressure level but the output will be i
25、n terms of mechanical vibration measured as an alternating force or force level. This standard defines a method of expressing the input/output ratio as an acousto-mechanical sensitivity level measured on a mechanical coupler according to the second edition of IEC Publication373: Mechanical Coupler f
26、or Measurements on Bone Vibrators. By means of information provided in this standard the performance of hearing aids with bone vibrator outputs which do not form an integral part of the hearing aid for example body worn hearing aids, may be measured in a similar manner to aids with air conduction ou
27、tputs as described in IEC Publication118-0. Where the bone vibrator forms an integral part of the hearing aid, or where it is attached in some fixed manner to the hearing aid (e.g.a headband type bone conduction hearing aid) 1) . performance cannot be measured in the same way as for body-worn aids,
28、due to the large dimensions of the mechanical coupler having to be in contact with the spectacle arm. This standard recommends a pressure method of controlling the input sound pressure level, to the hearing aid microphone. The second edition of IEC Publication373, describes the means of measuring th
29、e output from a bone vibrator. 1 Scope This standard specifies methods of measurement of the characteristics of hearing aids using bone vibrator output. 2 Object The methods described will produce a suitable basis for the exchange of information or for direct comparison of the electroacoustical char
30、acteristics of hearing aids using bone vibrator output. These methods are chosen to be practical and reproducible and are based on selected fixed parameters. The results obtained by the methods specified herein express the performance under the conditions of the test, but will not necessarily agree
31、exactly with the performance of the hearing aid under practical conditions of use. 3 General 3.1 Throughout this standard all sound pressure levels specified are referred to204Pa. When appropriate, sound pressure level will be abbreviated to SPL. 3.2 In this standard, reference is made to the follow
32、ing IEC publications: 4 Explanation of terms Terms other than those used in IEC Publication118-0 are given below. 4.1 Bone vibrator An electromechanical transducer intended to produce the sensation of hearing by vibrating the cranial bones. 1) Seenational foreword for details of textual error. Publi
33、cation68: Basic Environmental Testing Procedures. Publication118-0(1983): Hearing Aids, Part0: Measurement of Electroacoustical Characteristics. Publication118-7(1983): Hearing Aids, Part7: Measurement of the Performance Characteristics of Hearing Aids for Quality Inspection for Delivery Purposes. P
34、ublication263(1982): Scales and Sizes for Plotting Frequency Characteristics and Polar Diagrams. Publication373(): Mechanical Coupler for Measurements on Bone Vibrators.BS6083-9:1986 2 BSI 10-1999 4.2 Mechanical coupler A device designed to present a specified mechanical impedance to a vibrator appl
35、ied with a specified static force and equipped with a mechano-electric transducer to enable the alternating force level at the surface of contact between vibrator and mechanical coupler to be determined. 4.3 Vibratory force level (force level) Twenty times the logarithm to the base10 of the ratio of
36、 the r.m.s. value of the force transmitting the vibration to the reference value of1micronewton(14N), expressed in decibels. 4.4 Output force level (OFL) The vibratory force level produced at a specified frequency on a mechanical coupler by the bone vibrator of the hearing aid under test. 4.5 Output
37、 force level frequency response (force level curve) The OFL produced on the mechanical coupler by the hearing aid expressed as a function of frequency under specified test conditions for constant input sound pressure level. 4.6 Output force level for an input sound pressure level of90dB(OFL 90 ) The
38、 OFL at a specified frequency produced with an input sound pressure level of90dB and the hearing aid gain control in the full-on position. 4.7 Reference point (of a hearing aid) A point on the hearing aid chosen for the purpose of defining its position, normally the centre of the main sound entry to
39、 the aid. 4.8 Acousto-mechanical sensitivity At a specified frequency and under specified operating conditions the quotient of the vibratory force produced on the mechanical coupler by the hearing aid and the sound pressure at the reference point of the hearing aid. 4.9 Acousto-mechanical sensitivit
40、y level (AMSL) Twenty times the logarithm to the base10of the ratio of the acousto-mechanical sensitivity to the reference sensitivity of ; expressed in decibels. NOTETo calculate the acousto-mechanical sensitivity level (AMSL) from measurements made in this standard the following formula may be use
41、d: AMSL=OFLINPUT SPL where OFL is expressed in decibels ref.14N and sound pressure level to the hearing aid microphone in decibels ref.204Pa. 4.10 Reference test gain control position The setting of the hearing aid gain control that provides an output force level on the mechanical coupler151dB less
42、than OFL 90for an input sound pressure level of60dB at the reference test frequency of1600Hz. For certain hearing aids for which a higher reference test frequency is more appropriate (so called high-tone hearing aids)2500Hz shall be used. If2500Hz is used this shall be clearly stated. If the acousto
43、-mechanical sensitivity level available will not permit this, the full on gain control position of the hearing aid shall be used. 4.11 Basic force level frequency response curve The output force level frequency response curve obtained with the gain control in the reference test gain position and wit
44、h an input SPL of60dB. 5 Test equipment 5.1 Equipment for the measurement of the output force level The equipment used for measurement of OFL on the mechanical coupler produced by the hearing aid, shall comply with the following requirements: 5.1.1 For all measurements a mechanical coupler in accord
45、ance with the second edition of IEC Publication373 shall be used. 5.1.2 The output force level corresponding to hum, vibration, thermal agitation and other noise sources shall be sufficiently low to ensure that the reading shall drop at least10dB when the test signal is switched off. For this purpos
46、e a high-pass filter not affecting frequencies of200Hz and above may be employed. 5.1.3 The output indicator used shall give the r.m.s. indication within a tolerance of 0.5dB at a signal crest factor of not more than3. NOTE 1Under certain conditions it is necessary to use a selective measuring syste
47、m in order to ensure that the response of the hearing aid to the signal can be differentiated from inherent noise in the hearing aid. The use of the selective system should be stated in the report on test results. NOTE 2It is well known that the type of output indicator employed may influence the te
48、st results significantly if a non-sinusoidal voltage is being measured. Such non-sinusoidal voltages may be present when making measurements with high input levels. 5.1.4 The overall accuracy of the electronic measuring system following the mechanical coupler shall be within 0.5dB at a specified fre
49、quency. 1 N 20 Pa -BS6083-9:1986 BSI 10-1999 3 5.1.5 The calibration of the mechanical coupler shall be in accordance with the second edition of IEC Publication373. NOTEThe calibration of the mechanical coupler should be repeated sufficiently often, preferably at least once a year, to ensure that it remains within the permitted limits during measurements. 5.2 Equipment for automatic sweep frequency recording Reference shall be made to IEC Publications118-0 and118-7, as appropriate. 6 Test conditions 6.1 General The te
