The following contents specified in this standard are applicable to the calibration of bone vibrators for pure tone bone conduction audiometry. a) Reference equivalent threshold force level, equivalent to the hearing threshold of bone conduction audiometry for normal young people in otology. b) Basic characteristics of bone vibrators and their coupling methods with subjects and mechanical couplers. c) Basic characteristics and baseline level of masking noise applied to the non-test ear. GB/T 4854.3-1998 Reference zero level for acoustic calibration of audiometric equipment Part 3 Pure tone reference equivalent threshold force level for bone vibrators GB/T4854.3-1998 Standard download decompression password: www.bzxz.net
The following contents specified in this standard are applicable to the calibration of bone vibrators for pure tone bone conduction audiometry. a) Reference equivalent threshold force level, equivalent to the hearing threshold of bone conduction audiometry for normal young people in otology. b) Basic characteristics of bone vibrators and their coupling methods with subjects and mechanical couplers. c) Basic characteristics and baseline level of masking noise applied to the non-test ear.

GB/T4854.3---1998
This standard is based on the international standard IS0389-3:1994 (E)\Acoustic calibration audiometric equipment reference zero level Part 3: Pure tone calibration equivalent level\ and its No. 1 technical correction (1194), and revised the national standard GB/11166989\Acoustic calibration pure tone bone conduction audiometer standard zero level\. It is technically equivalent to the international standard. The preparation of GB/T11669-89 was based on experimental verification and referenced to the international standard ISO7565:1987, which has been revised and replaced by ISO889-3. The revision of ISO this time is the serialization of audiometric equipment calibration standards. The actual modification is very small, and the basic data has not changed. Our current revision and preparation are also making the serialization of audiometric equipment zero level standards in line with international standards. Therefore, the standard adopts ISO 389-3:1994 (E) equivalently. Compared with the old national standard GB/T11669-89, the basic data and other contents have been increased. This standard replaces GB/T11669-89. The five appendices in this standard, Appendix A, Appendix B, Appendix C, Appendix I and Appendix E are all new. This standard is proposed and approved by the National Technical Committee for Acoustic Standardization. The drafting units of this standard are: Institute of Psychology, Chinese Academy of Sciences, Institute of Ear and Laryngeal Guidance, General Hospital of the Chinese People's Liberation Army, Institute of Acoustics, Chinese Academy of Sciences.
The drafters of this standard are Fang Zhi, Gu Rui, Zhang Ruwei. GB/T 4854. 3—1996
ISO Foreword
The International Organization for Standardization (ISO) is a worldwide joint organization composed of national standardization committees (ISO member countries). The formulation of international standards is usually completed by ISO technical committees. Each member country has the right to participate in a technical committee when it is interested in a standard determined by a technical committee. International organizations, both governmental and non-governmental, that are in contact with ISO may also participate in the work. ISO maintains close cooperation with the International Electrotechnical Commission (IEC) in all aspects of the promotion of electrotechnical standards. Draft international standards adopted by technical committees shall be distributed to member states for voting. A draft international standard requires at least 75% of the member states to vote in favor before it can be published as an international standard. The international standard ISO889-3 was drafted by ISO/TC43 Technical Committee on Acoustics. This version of ISO389-3 cancels and replaces ISO7566:1987, with only slight modifications to it. The general title of ISO389 is "Acoustics - Reference zero level for calibration of audiometric equipment", which includes the following parts: Part 1: Basic equivalent valve sound pressure level of pure tone for on-ear headphones; Part 2: Basic equivalent valve sound pressure level of pure tone for insert earphones; Part 3: Basic equivalent sound pressure level of pure tone for bone vibrators; Part 4: Basic sound pressure level of narrow-band masking noise; Part 5: Basic equivalent sound pressure level of pure tone in the frequency range of 8 to 16 kHz; Part 6: Basic equivalent sound pressure level of short-tone test signals; Part 7: Basic hearing threshold for white-field and diffuse-field audiometry. ISO389:1991 will be republished as Part 1 of this standard series. Annexes A, B, C, D and E of this part of ISO389 are all indicative. GB/T4854.3-1998
In clinical and certain other audiometric tests, it is often necessary to compare the air conduction and bone conduction hearing levels of an individual. For this purpose, bone conduction sound is provided by an electromechanical vibrator placed only on the subject's mastoid process or forehead. This standard specifies a base zero level, i.e., a reference equivalent threshold level, for bone conduction audiometry. During audiometry, the bone vibrator is usually placed on the mastoid process or forehead. The two locations may have different values ​​of the reference equivalent threshold level (see Appendix C). Bone conduction audiometry must specify the static position of the bone probe on the subject's head or on the electromechanical coupler and certain geometrical features of the vibrator end face. In addition, since the vibration of the bone vibrator may be heard by the non-test ear, it is often necessary to apply masking noise to it. Therefore, there should be appropriate provisions for masking noise as a supplement to the basic equivalent threshold level. Due to the "blocking effect", when the earphone provides masking noise, the hearing of the non-test ear will be reduced, which requires increasing the sound level of the masking noise to offset the blocking effect. Using this reference zero-level to calibrate the audiometer will ensure that the bone conduction hearing level measured from people with no hearing loss or pure sensorineural hearing loss (that is, no damage to the middle and outer earphones) can be consistent with the air conduction hearing level measured by the same person according to the GB4854-84 standard. Of course, due to the biological variation in the transmission of sound through the outer ear, middle ear and head, the air conduction and bone conduction of any individual among the subjects cannot be exactly consistent, but this standard will ensure that the average system of these subjects is consistent. The deviation will be reduced to the minimum that can be used practically. This standard is an estimate made by ISO) based on the technical data provided by the experimental units of three countries. The reading test methods they used are essentially the same from the perspective of the cases introduced. Numerical investigations have shown that the experimental results are consistent. Therefore, it is possible to standardize the reference equivalent hearing level as the reference zero level to apply to all bone vibrators with characteristics similar to those used in the above experimental cases in audiometry. The system changes caused by this prudent simplification are very small compared to the normal step size (5dB) of the audiometer to control the hearing level. 1 Scope
National Standard of the People's Republic of China
Acoustics Calibration Audiometric Equipment Reference Zero Level
Part 3 Reference Equivalent Pure Tone Level of Bone Vibrator Acoustics--Reference The following contents specified in this standard are applicable to the calibration of bone vibrators for pure tone bone conduction audiometry. a) The quasi-equivalent threshold level is equivalent to the hearing of young people with normal otology for bone conduction audiometry. Reference 1: The reference for the determination of the quasi-equivalent threshold level between the forehead and mastoid is listed in Appendix C. b) The basic characteristics of the bone vibrator and its coupling method with the subject and with the mechanical coupler. c) The basic characteristics and normal level of the masking noise applied to the non-test ear. The actual guidance for the use of this standard in the calibration of audiometers is listed in Appendix A. Note 2: The standard method for bone conduction audiometry is specified in GB/T16403-1996, and the reference standard is GB/T 4854. 3-1998
eqIS0389-3.1994(E)
Replaces GB/T1166989
The texts included in the following standards are referenced in this standard and constitute the series of this standard. When the standard is published, the versions shown are valid. All standards will be revised. All parties using this group of standards should explore the possibility of using the latest versions of the following standards. GH3241-82 1/1 and 1/3 octave filters for sound and vibration analysis GB 4854-84 Standard zero level for calibration of pure tone audiometers GB 7341-87 Audiometers
GB/T15951-1995 Force coupler for bone vibrator measurement GB/T16402-1996 Acoustic insert earphones Pure tone reference equivalent sound level GB/716403-1996 Acoustic measurement methods Pure tone air conduction and bone conduction audiometry Basic audiometry IS0389-1:199-1 Reference level of narrow-band masking noise 3 Definitions
This standard adopts the following definitions.
3.1 Bone conduction
Mechanical movement of the facial bones to transmit sound to the inner ear. 3.2 Bone vibrator
A transducer that converts electrical oscillations into mechanical vibrations, which is closely attached to the bone structure of the human body (usually the mastoid sinus). 3.3 Fortelevel
The common logarithm of the ratio of the root mean square value of the vibration transmission force to the fundamental value (1N) multiplied by 20, in decibels (d). 3.4 Mechanical coupler Approved by the State Administration of Technical Supervision on March 18, 1998, and implemented on October 1, 1998
GB/T 4854: 3—1998
A calibrator that simulates the force impedance characteristics of the breast/forehead region of the human head in the frequency range of 1258000Hz, used to calibrate the zero-level bone conduction hearing test and measure the sensitivity, frequency response and harmonic distortion of bone vibrators. Note 3: Mechanical transducers are specified in GB/T15951.5 Equivalent instantaneous force level (monaural audiometry) equivalent threshold force level (monaural audiometry) For a certain human ear, at a specified frequency, for a bone vibrator of a certain structure and when the bone vibrator is pressed onto the mastoid with a certain force, the vibration force level of the bone vibrator in a specified mechanical coupler is equivalent to the hearing when the bone vibrator is excited by a table voltage on the mastoid. 3-6 Reference equivalent force level refercncccqurvalent threshold force level (RETFl) At a specified frequency, using a bone vibrator and mechanical coupler of a specified structure, the average value of the equivalent force level of a sufficient number of male and female subjects with normal otology between the ages of 18 and 30. 3.7 (pure tone > hearing level) At a given frequency, the pure tone alternating force level (sound pressure level) produced by a transducer of a specified type in a specified manner of use in a specified mechanical coupler (or acoustic coupling device, sub-mold or artificial ear) is equal to the corresponding reference equivalent force level (or reference equivalent threshold sound pressure level) of bone conduction (or air conduction).
Sign: 4: This definition can be extended to apply to traction noise, 3.8 Blockage effect cclnsloh cffect
Blocking the ear with earphones or plugs: A closed air-filled cavity is formed between the outer ear and the earphone or in the external auditory canal, which reduces the hearing level of the ear. The blocking effect is more obvious at low frequencies. 3.9 Masking
(1) The hearing level of a sound increases due to the presence of a masking sound. (2) When measuring the hearing of one ear, a method of adding noise to the other ear to avoid affecting the hearing of the other ear is often used: 3.10 Masking noise baseline level f masking naise is the level of 1/3 octave band noise produced by air conduction, expressed in terms of hearing loss, which makes the pure tone of the noise center frequency audible to normal otologists with an air conduction hearing threshold level of zero at a hearing level of less than 35 dB, that is, 50% of the people are aware of it in repeated experiments. Note: The value of 535 dB is arbitrarily selected from the range used in the experimental research on which the standard is based, and there is no intention to use this level of masking noise in clinical practice. The relationship between the masking noise level and the pure tone masked by it has been specified in 50389-1. 3.11 Critical bandwidth criticalbandwidth is the widest frequency band of a continuously distributed random noise with a constant frequency level, within which the loudness of the noise is not affected by its band.
3. 12 Vihratactile threshold level The alternating force level that enables a person to respond with 50% accuracy in repeated experiments on skin motion sensation. 3.13 Noise when measured with a fixed bandwidth, the spectrum is continuous and uniform, the power spectral density of the noise does not change with frequency. 4 Reference equivalent force level 1 List the reference equivalent force levels of bone vibrators located at the mastoid region, which are obtained from the measurement and analysis of normal otolaryngology at the mastoid region under the conditions described in Chapter 5: 125031 1) 0.5 dB approximation. GB/T 4854. 3—1998 Reference equivalent force level of bone vibrators located at the mastoid region Reference equivalent force level (base value μN) 2) The values ​​for these frequencies are obtained by interpolation.
3) These numerical values ​​are the results of one laboratory. Note
6 000:
Benchmark equivalent force level
(benchmark value is 1N)
It must be emphasized that the data listed in Table 1 are derived from the results obtained by using bone vibrators of different electromechanical properties and different types on the head in the specified force formula. The masking level used in the three studies is different. The compensation method used may also affect the differences between the studies. The values ​​of frequencies below 8250Hz are not specified in this standard. The results of one laboratory are listed in Appendix D for reference. 5 Test conditions and requirements
This chapter specifies the conditions and requirements that should be met when using the benchmark equivalent force level. 5.1 Bone vibrator
The bone vibrator should have a flat and flat end surface with a nominal area of ​​175trlI. When in contact with the head of a subject with normal ear and external ear function, the sound level of the airborne sound radiated by it should be low enough so that the difference between the true bone conduction hearing level and the erroneous air conduction hearing level caused by the bone vibrator is equal to or greater than 10dB. If this condition is not met at all frequencies, the subject's external ear should be given an earplug to eliminate unnecessary sound radiation when testing the affected frequency. Due to the plugging effect, the use of earplugs is limited to frequencies above 200Hz. 5.2 Wearing of bone vibrator
Fix the bone vibrator on the breast with a headband, the nominal static force should be 5.4, the bone vibrator should be placed on the breast sinus, not touching the ear, and adjusted to a stable position.
5.3 Mechanical coupler: The mechanical coupler should comply with the provisions of GB/T15951 (see Appendix B. Especially B3). 5.4 Test signal
The alternating force signal generated by the bone vibrator according to the micro-excitation level in Table 1 shall not exceed 1% when measured on a mechanical coupler. It shall not exceed 2 Hz at 500Hz to 1000Hz. It shall not exceed 2 Hz at 250Hz to 400Hz and above 1250Hz. 5.5 Masking noise
The masking signal is generated by random self-noise through a filter with a frequency of 1/3 times the frequency of each test pure tone listed in Table 1.
5.6 Masking transducer
The masking noise signal shall be sent to the non-test ear by a press-on earphone or plug-in earphone that complies with GB4854 or GB/T16402. 5.7 Wearing of masking transducer
The transmission noise is used by the headband of the fixed bone vibrator worn at the same time. If insert earphones are used to transmit the masking noise, the masking noise line level specified in G13/116402 shall be given in accordance with 5.8. The masking noise line level for average otological training should be given with the baseline level specified in 3.10. In 9: Due to the different widths of the critical bandwidths, in principle, the value depends on the center frequency of the forehead band, but each 1/3 octave band has an hearing level of 40 dB, which is roughly equal to the specified baseline level. The difference between the hearing level of the noise band and the pure tone hearing level mentioned in 3.1 is about 51R. This difference represents the amount of noise that the masking noise exceeds the 50% required for the pure tone to be correctly perceived in the critical bandwidth (see 150)389-4). The baseline level can be reported as the reference equivalent sound pressure level specified in GB4854 or GB/T16402 plus 40dB according to the type of headphones used for masking transducers, that is, the dB sound pressure level relative to 20μPa expressed in GB/T 4854. 3—1998
Appendix A
(Indicative Appendix)
Notes on the calculation of the reference equivalent threshold level values ​​The values ​​of the reference equivalent threshold level specified in this standard are derived from the results of three independent experimental studies submitted to ISO/TC13 Technical Committee on Acoustics. The main points of the test are listed in Table A1. Table A1 Research on the values ​​of the reference equivalent threshold level Test data
Bone detector model
Masking headphone model
Masking noise level
Number of tested ears
Number of tested subjects
Test frequency
References [1]
B-71->
TDH39s1
Effective level 5
0. 25, (. 5, 1
I) American Rendient Corporation y product 2) Product of Grahner. Pracitrnic GmbH, Germany. 3) Product of Telephonics Cotpxratiun, USA. 4 Product of Tieyer AG, Germany.
5) The definition of "effective masking level" can be found in Appendix A4 of Reference 4.
Reference [2]
25dB and 40dB
Perception level
0, 25,0. 5,1
Reference [3]
1251Iz, 250Hz40 Effective level
High frequency is referenced dB effective level
o.125,0.25,c.5,o.75,l.1.5,2.3,4.5.5,6.3+8
The bone conduction audiometric values ​​used in the preparation of this standard have not been corrected for the deviation between the air conduction audiometric level and (B) of the subjects. For further details on the derivation of the reference equivalent audiometric level, see reference [21. Appendix B
(Prompt Appendix)
Application Guide for Reference Zero Level Calibration of Bone Conduction Audiometers B Overview
When the bone conduction audiometer is calibrated according to this standard and the hearing of the otologist is measured under the conditions specified in Chapters 4 and 5, as long as the background noise in the test room and the value determination method are in accordance with the provisions of GB/T16403--1996, an average audiometric level of 0dB should be obtained. B2 Selection and wearing of bone vibrator
According to the provisions of GB7341, the area of ​​the circular contact plane should be 175mm ± 25mm. For comfortable wearing, the bone The end face of the alarm should have a rounded edge (e.g., optical path (.5mm)). - Palace said that the hearing aid type inertial response bone vibrator has only limited low-frequency output under the condition of allowable distortion, and is therefore often not suitable for audiometry below 250Hz; the larger key-type bone vibrator is superior in this respect, but due to its larger size, it will produce more unwanted high cheek sound reflections.
The static force of the headband used should be 5.4N ± 0.5N. Note 10: A headband that provides a 6.4V force for an average head width of 145nm (for breast) or 190nm for forehead). The total passband used for adult testing should comply with the above tolerances
B3 Calibration of bone vibrator
GB/T4854.3-1998
According to the provisions of G37341, the static force applied by the bone vibrator to the mechanical coupler becomes 5.4 N + 0.5 N. When the test is done, the appropriate operating temperature that both should reach is 23°C ± 1°C as specified in GB/T15951. Due to the high heat capacity of the mechanical device, it may take several hours for the system to reach thermal equilibrium before calibration. Any deviation from this temperature can only be tolerated when data are available on the temperature dependence of the performance of a particular type of bone vibrator on the mechanical coupler. B4 Selection and wearing of masking transducers Www.bzxZ.net
For convenience, the same machine used to determine the air conduction noise can be used to give the non-test ear a masking noise. If a pressure-on-ear headset is used, the headband force should be 4.5N ± 0.5N. In this way, the headband force should be 4.5N ± 0.5N as specified in GB 4854 or GB/T 16402 calibrated air conduction headphones can correctly give the hearing level of masking noise.
B5 Masking Noise Source
The bandwidth tolerance defined by the 3dB drop point of the spectral density is recommended to be U~-6 octaves. In order to generate 1/3 octave band masking noise from broadband white noise, the filter characteristics should comply with the provisions of GB3241. Appendix
(Notes)
Tentative difference in the reference equivalent hearing level between the forehead and mastoid parts of the bone vibrator
Bone vibrator Provisional values ​​for the difference in the basic equivalent level between the forehead and mastoid sites are given in Table C1. They are derived from bone conduction hearing thresholds of normal otologists under the conditions described in Chapter 5. NOTE I1 The values ​​in Table C1 are obtained from the results of four experimental studies submitted to ISO/TC 43. The key points of these experiments are given in Table C2. Table C Provisional values ​​for the difference in basic equivalent level between the forehead and mastoid sites RETFL (forehead > RETL (mastoid) P
1) 0.5 dR Approximate value,
2) The values ​​for these frequencies are taken from the reference values.
3) These frequency values ​​are derived from the results of only one laboratory, frequency
RETFL (forehead) minus RETFL (mastoid)
Experimental data
Bone sensor model
Test ear
Number of testers
Test frequency
GB/T 4854-3—1998
Table C2 Research on the values ​​of RETFL (forehead) minus RETFI (mastoid)
Reference [5]
250,500,1 000,
2 000.3 000,4 000 *
Reference [6]
250.500,1 000,
2 000,3 000.1 000
Note: The result of 4 000 Hz is not considered because the air radiation of the bone conduction device is not taken into account. Appendix D
(Suggestive Appendix)
References [3]
125,250,500,750,
1 000,1 500.2 000,
3 000,4 000.5 000,
6 000+6 300.8 000
Bone conduction listening at frequencies below 250 Hz
References [?
250,500,730.1 500
2 000,3 000,1 Bone conduction measurements at frequencies below 000
250 Hz are of limited use because of the high distortion of the signals of current bone vibrators of the habitual response type (see B2 of Appendix B) and because the results of tests on subjects with hearing loss may be misinterpreted by the use of tactile sensors. However, reference equivalent force levels of bone vibrators at the mastoid site for frequencies between 125 Hz and 200 Hz, and the difference in reference equivalent force levels between bone vibrators at the forehead and mastoid sites, have been determined (see Appendix A and Appendix C) and are listed in Appendix D1 for reference. They are derived from bone conduction hearing instruments measured by an otologist under the conditions specified in 5.1 to 5.3 and 5.5 to 5.8. The test signals used have a total distortion of no more than 2 % as measured in accordance with 5.1. Table D1 The difference between the reference equivalent force level at the mastoid and the reference equivalent force level between the forehead and the mastoid of the bone vibrator
130.5d Nearest value.
2) The values ​​of these frequencies are obtained by interpolation.
RETFL mastoid)
(reference value μN)
Appendix E
(Appendix for presentation)
Cai Kao Literature
RETFL[front flip) minus RETFL(mastoid 1
(reference value: 1LN)
E1J Irks,I). I). .Lybarger,SF .Olsen, WO aul Bulings, BL Bone conduetion calilbrallon-presentstatus. J.Speech Hearing Disorrters,44(2).1979,pp. 113-155.2TRobinson,DWand Shipton,MS A standard determination of paired air andi bone conductionthresholds under different masking nvise conditions. Audiology+21,1981.pp. 61-82.i3LRichie,I.aslBrnkuau.K.Thresholl uf hsefinbybonc conductionGB/T 4854.3—1998
national standardizalion Scan.Audial. t10,1981,pp.235 237.[4] ANSI 53:1972.An artificial headbone for the calibration ol audiotneler hae vihraler s. [AmcricanNational Standards lnstitute].[5 Frank,T, Clinical note,Foreheacl versus mastoid threshold d.fferences with a rircular tipped vihratar.EarandHearing,3,1982,pp.91-92.[6] Heughton,PM and Pardoe,K. Normal pure tonc thresholds for hcaring by bone curnducetiun. Brt.J. Audiol. 15,1981,pp, 113 121.[?Brinikin,K. and Richter,.Determinatron of the norll thteshold of hearing hycn conduc-tion using different types af bone vibrators. Audiological Acoustics.22.1983,Pp, 62 85 and ll1122.
[8 ISO 389-4: 1994,Acoustics-referernce zero for the calihration nf audiomctric cqulpments-Part A:reference levels for narrow-band rnaskiig ibise._9] IEC 645 l:1992,Audiomelers --Part 1:Pure-tone audometers.
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