Acoustics--Reference zero for the calibration of audiometric equipment--Part 1: Reference equivalent threshold sound pressure levels for pure tones and supra-aural earphones
Some standard content:
GE/T4854.1—1999
This standard is equivalent to the international standard IS0389-1.1991 "Reference levels for acoustic calibration of audiometric equipment - Part 1: Reference equivalent threshold sound pressure level for pure tone of on-ear headphones", which is a revision of GB/T4854-1984 for the standard zero level used to calibrate pure tone audiometers. This standard is the first standard in the standard series of reference zero level for acoustic calibration audiometry equipment. The standard series GB/T4854 has 7 standards under the general title "reference zero level for acoustic calibration audiometry equipment". They are: GB/T4854.1 Reference zero-level on-ear headphones for acoustic calibration audiometry equipment Reference equivalent threshold sound pressure level of pure tone (GB/T16402 Reference zero-level insert earphones for acoustic calibration audiometry equipment Reference equivalent sound pressure level of pure tone GB/T 4854.3 Reference zero-level bone vibrator for acoustic calibration audiometry equipment Reference equivalent sound pressure level of pure tone GB/T4854.4 Reference zero-level narrow-band masking noise for acoustic calibration audiometry equipment Reference level of pure tone in the frequency range of 8-16kHz for acoustic calibration audiometry equipment Reference equivalent sound pressure level of pure tone in the frequency range of 8-16kHz for acoustic calibration audiometry equipment 4854.6
GB/T 4854.7
Acoustics: Reference zero-order free-field and diffuse-field audiometry for calibration of audiometric equipment Reference audiometric performance
When the 2nd standard in the 1st series was formulated, it had not yet formed a standard series. When GB/T 18402 is revised, its standard number will be changed to the 5th and 6th standards in the GB/T 4854.2.2 series to be determined. This standard will replace GB/T4854-1984 from the date of implementation. Appendix A to this standard Appendix A and Appendix B are both informative appendices. This standard is proposed and coordinated by the National Technical Committee on Acoustics Standardization. The originating units of this standard are the Institute of Acoustics, Chinese Academy of Sciences, and the Chinese Academy of Basic Sciences. The main drafters of this standard are Zhang Jucai, Zhang Ruwei, You Yang, and Shuai Zhengzang. GB/T4854.1—1999
ISO Foreword
The International Organization for Standardization (ISO) is a worldwide joint organization composed of national standardization committees (ISO member states). The formulation of international standards is generally completed by ISO technical committees. Each member country has a technical International Standards are published as International Standards when at least 75% of the member states vote in favor of them. International Standard ISO 389 was drafted by ISO/TC43 Technical Committee on Acoustics. This edition cancels and replaces the second edition (150 389, 1985). Supplement 1 (published in 1985) and Supplement 2 (published in 1986) were merged.
Appendix A and references to this international standard are for reference only. The general title of ISO 389 is "Acoustics - Reference zero level for calibration of audiometric equipment", which includes the following parts: Part 1: Reference equivalent threshold sound pressure level of pure tone for on-ear headphones; Part 2: Reference equivalent threshold sound pressure level of pure tone for insert earphones; Part 3: Reference equivalent threshold sound pressure level of pure tone for bone vibrators; Part 4: Reference level of narrow-band masking noise; Part 5: Reference equivalent sound pressure level of pure tone in the frequency range of 816kHz; Part 6: Reference equivalent sound pressure level of short-term acoustic test signals; Part 7: Reference level for white-field and diffuse-field audiometry (Parts 5 and 6 are pending)
GB/T 4854.1—1999
This standard, the first edition GB/T 48541984, is equivalent to the supplement 1 of ISO 389, the first edition (1975) and ISO 389:1975/Add.1—1983
The vast majority of data on earphone-coupler combination mentioned in ISO 38, the first edition, are no longer applicable. 1SQ Member States agreed to delete the obsolete data. This standard only contains two sets of earphones (Teleplanics with ear pads MX41/AR (or 5) type TDH39 and Beyer [T48)) and the base-thrust equivalent sound pressure level (RFTSPI.) of the acoustic coupling cavity to which they are applicable, which are still widely used for audiometry. The difference between the two sets of retained data is mainly caused by the difference between the acoustic characteristics of the acoustic cavity and the acoustic characteristics of the average human ear. According to the same principle, the headphone models not included in 1S () 389 can only be compared subjectively with the specified headphone models to obtain appropriate data. In principle, as long as the headphone is referenced to a simulated ear that truly simulates the acoustic characteristics of the average human ear, it can independently provide a RETSPL value. Devices designed for this purpose were standardized in 1970 in IEC 318:1970 (now IEC 60338). The resulting RETSPL provides a standard audiometric zero level for any type of earphone within a wide range of tolerances. The derivation of these reference zero levels and the source of the data are given in Appendix A for reference. 1 Scope
National Standard of the People's Republic of China
Acoustics- Reference zero for the calibratlon of audlometric equipment
Part 1: Reference equivalent threshold sound pressure levels for pure tones and supra-aural earphones GB/T 4854- 1— 1999
tqv Iso 389-1:1991
Replaces GB/T 4854—1984
To promote uniformity and consistency in the presentation of hearing level measurements throughout the world, this standard specifies the "reference zero level" for the scale of hearing threshold levels used by all audible meters.
The data described in this standard can be used directly for the calibration of audible meters, that is, the responses of two different standard headphones measured in the coupling cavity in GB/T7342, and the responses of other over-ear headphones measured on real ears in GB/T7611. This standard is based on the work of several standard laboratories responsible for the promotion of audiometric standards and scientific publications. The evaluation provided by the publication. The recommended reference level is derived and should be found in Appendix A.
2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision. The possibility of using the latest versions of the following standards should be explored at all points in using this standard CB/T7342-1987 IEC temporary reference coupler for audiometric headphones (egFC303: 1970) GB/T 7582-1087 Acoustics Otology Air conduction hearing of normal people and its relationship with age and gender (NE9 IS07029:1981) GB/17614-1987 Wideband type real ear for calibrating audiometric headphones (E9 [EC318;1970) GB/T16403-1996 Acoustic audiometry methods Pure tone air conduction and bone conduction hearing thresholds Basic audiometry method (egvISO8251-1:1989) 3 Definitions
This standard adopts the following definitions.
3.1 Air conduction
The process of sound passing through the outer ear and middle ear to the inner ear in the air. 3.2 Acoustic coupling cavity Acoustic coupling cavity has a specified shape and volume, which is used to calibrate the earphone. The sound pressure in the cavity is measured by a calibrated microphone connected to it.
Note: The specifications of the acoustic coupling cavity can be found in GB/T 7342.3.3 Artificial ear artificialer
Approved by the State Quality and Technical Supervision Department on March 8, 1999 and implemented on September 1, 1999
GB/T 4854. 1 1999
Equipment for measuring headphones, which makes the acoustic impedance of the headphones close to the average acoustic impedance of the human ear. Method
1 There is a microphone in the artificial ear to measure the sound pressure generated by the headphones. 2 For the provisions of artificial ears, see CB/T7614.
3.4 Hearing thteshold
The lowest sound pressure at which a person can correctly discriminate a given signal with a certain percentage in repeated tests with a specified signal under specified conditions. The characteristics of the signal, the way it reaches the listener and the point where the sound pressure is measured must be stated. Notes
1 Unless otherwise stated, the ambient noise reaching the human ear is considered to be negligible. 2 Hearing thteshold is generally expressed in decibels relative to 20Ps. 3 Repeated tests refer to methods using a constant pressure sound source. Other psychophysical methods can also be used, but the method of use should be stated. 4- Critical score 50%
3.5 Otologically normal person A person with normal health, no symptoms of ear disease, no ear canal obstruction, no history of excessive noise exposure, no ear medication or family hearing loss.
3.6 Equivalent threshold sound pressure level (manaural earphone listening)
The sound pressure level produced by a specified type of earphone in a specified acoustic coupling cavity or artificial ear when a specified force is applied to the earphone at a specified frequency and a voltage corresponding to the hearing voltage is excited. 3.7 Reference equivalent threshold sound pressure level The mode value of the equivalent hearing sound pressure level of a sufficient number of subjects of both sexes with normal otology between the ages of 18 and 30 at a specified frequency.
Note: The relationship between air conduction hearing level and age can be found in H/T 7562. 3.8 (Pure tone) Hearing level (of apure tone) The difference between the pure tone sound pressure level produced by the earphone in a specified acoustic coupling cavity or artificial ear at a specified frequency and the corresponding reference equivalent hearing sound pressure level for a specified type of earphone and a specified method of use. 3.9 Hearing threshold (of a given ear) Hearing threshold (of a given ear) measured in a specified manner at a specified frequency using a specified type of earphone. Note: Examples of suitable test conditions are given in the technical requirements of GE/T7583 and GH/T164034.
4.1 General
The reference equivalent hearing sound pressure level depends on the type of earphone and the type of acoustic coupling chamber used to calibrate it. 4.2 Beyer DT 48 and Telephonics TDH 35 earphones The reference equivalent sound pressure levels recommended for these two different machines in a coupling chamber meeting GH/T7342 are shown in Table 1. Beyer DT48 earphones must be equipped with flat ear pads when they are placed on the human ear and with adapters when they are placed on the coupling chamber. TDH39 earphones must be equipped with ear pads MX41/AR (or 51 type) when they are placed on the human ear and on the coupling chamber. The earphones shall be subjected to a nominal static force of 4.5 N ± 0.5 N excluding their own weight and shall be silent when acting on the coupling cavity. 1] The specifications of a suitable adapter are given in the reference [1. GB/T 4854-1-1999
Table 1 Recommended values of reference equivalent hearing threshold sound pressure level in the coupling cavity of GL/7342,
Headphone type
Reference equivalent hearing threshold sound pressure level, dB (base sound pressure i20uPa) 47.5
Beyer [r 48 with flat ear pads
Telephonies TDH sst
with MX/41AF (or 51) type 4 pads
1) In order to match and produce the same mechanical response as in the 9 coupling cavity, the filter cloth of the TDH39 earphone was changed in 1063. At this time, about 1000 pairs of headphones were produced with unmatched ferrules. The data given in this International Standard are the average values of several pairs of headphones produced before and after 1960.
Note: The values in the table are the median. 5 The nearest value is taken
4.3 Other supra-aural headphones bzxz.net
The recommended values of the equivalent sound pressure level of the base focal point of supra-aural headphones in the artificial ear that conforms to GB/T7614 are shown in Table 2. These values apply to headphones that meet the following requirements (excluding headphones specified in 4.2 to avoid aliasing): a) The headphones and pads (if available) should be axially symmetrical; b) The structure and material should provide a good acoustic seal between the headphone (or its ear pad) and the human ear; c) When placed on a flat surface, the contact circumference of the headphone (or its ear pad) should be comparable to the front-to-back diameter of the human body; d) The headphone (or its ear pad) should not have any part that protrudes from the plane given in c), and its top should be close to a truncated cone; e) The earphone or its ear pad (if available) should be in contact with the GB/T 7614 artificial ear contour meter at a diameter of 2m; Note 1. The meaning of this requirement is that the vertical angle tangent to the earphone contour of more than 25num will be greater than 113%f. If there is an ear pad, the material used should not be too soft to avoid significant deformation. The earphone is tested on a real ear. When the static force changes from 5N to 10N, the change in the apparent sensitivity level of 1kHz should not be more than 0.2dB;) When the earphone or its ear pad (if available) is placed on the human ear, the contour of the machine should be in contact with the auricle, but not with the head tissue of the auricle:
Note 2: This requirement does not include over-ear headphones. GB/T 4854.1—1999
h) The provided headband should be able to ensure that the earphones are subjected to a static force of 4.5N±0.5N on the ears. The benchmark equivalent audible sound pressure level shall apply when the earphones are coupled to the simulation under the following conditions: a) the earphones and the simulation are coaxial and the ear axis is perpendicular to the ground; b) no sound
c) use a nominal static force of 4.5N±0.5N excluding the weight of the earphones. Table 2 Reference equivalent hearing threshold sound pressure level on the simulated H circuit of GB/T 7614, frequency, Hz, reference equivalent hearing threshold sound pressure level, d13 (reference sound pressure: 20 μPa) Note: The values in the table are approximate values of C.5, frequency, Hz, 25°C, 0°C, reference equivalent hearing threshold sound pressure level + dB (reference sound pressure: 20 μPa) W1 Derivation A1.1 Overview GB/T 4854. 1 1999
Appendix A
(Informative Appendix)
Regarding the derivation and application of the recommended reference levels, it should be particularly noted that the reference equivalent listening valve sound pressure levels given in Tables 1 and 2 are confirmed as representative of the same level as far as possible by existing data. The inconsistency between them is mainly caused by the difference in the acoustic characteristics of the coupling chamber and the artificial ear. A1.2 Octave Band Frequencies and Additional Audiometric Frequencies 1500 Hz, 3090 Hz and 6000 IIz The reference equivalent listening sound pressure levels for BcycrDT48 headphones given in Table 1 correspond to the average values of 15 publications or other measurements notified to the International Organization for the Promotion of Standardization from 1950 to 1961. These data were obtained through the collaborative research of the following five standards laboratories: France Telecom National Research Center, German Institute of Technical Physics, British National Physical Laboratory, US National Bureau of Standards, and the All-Union Metrology Institute of the Soviet Union. The reference equivalent hearing sound pressure levels for Telephonics TIDH 39 headphones given in Table 1 are obtained by subjective balance method. See references [2] to [5] for details. The reference equivalent hearing threshold sound pressure levels given in Table 2 are the average results of transition measurements of several samples of 6 types of headphones. The sound levels produced in the GB/T7342 acoustic coupling cavity and the GB/T7611 sound chamber were compared by the following laboratories using the same electrical excitation for the headphones: Navi Hearing Institute, Swedish Rollins Institute, US National Bureau of Standards, UK National Physical Laboratory, German Institute of Technology Physics. See reference [6] for details. A1.3 Supplementary frequencies The reference equivalent hearing sound pressure level values for supplementary frequencies are derived by internal method from the values specified for the octave band frequencies and the additional audiometric frequencies 1500Hz, 3000Hz and 6000Hz, and are supported by some experimental data. In the frequency range 125 to 1 000 Hz, the interpolation method is based on the assumption that the relationship between the reference level (dB) and Ig() is a cubic polynomial. Linear interpolation is performed for Table 1 in the frequency range 1 000 to 8 000 Hz. The linear interpolation for Table 2 uses the range 11 000 to 4 000 Hz. The data for the higher frequency range are obtained experimentally. Note: The following laboratories provided experimental data: the Institute of Health and Welfare, the Swedish Regional Administration of the German Institute of Technology, and the University of Technology in Denmark. For details, see references [Ting--[10]. A2 Application
A2.1 For the calibration of an audiometer equipped with a type of earphone mentioned in Table 1 or specified in 4.3, the audiometer may be calibrated using the reference equivalent threshold sound pressure level recommended in the corresponding table using a coupling or artificial ear of the specified type. The headband used shall provide a nominal static force L of 4.5 N ± 0.5 N when the earphone is on the ear. NOTE: A headband capable of providing a force of 41.5 N for an adult subject with an average head width of 145 mm will normally meet this tolerance. A2.2 For an audiometer equipped with a type of headset neither mentioned in Table 1 nor specified in 4.3, the reference equivalent threshold sound pressure level for that type of headset shall first be determined. Usually appropriate "equal loudness balance" or "audio balance" techniques are adopted, and the headphones are compared subjectively with the type of speakers discussed in Chapter 4. The details of the technical procedures and equipment for this work should be provided by the manufacturer for reference or consulted with the relevant standards laboratory.
GB/T4854.1—1999
Appendix B
(Suggestive Appendix)
Art Examination Literature
[i1JMrass,H.andDiestel,HGAcustica,9,1959pp.61--64.[2J Weissler,PG Iniernational standard referenre zero for audiometers.J. Acoust. Soc, Amcr. , 44,1968,pp. 261-~275.
[3] Cox,Jr. tJ. R. and Bilger .R, C. Suggcstion relative te the standardization of ness-balance dalafar the trlephonics TTH-39 earphone,J. Acoust. Soc. Amer.,32.1960,pp. 1081~1082.[4J Whittle,l.. S. and 1'elany.MF Hquivalent. threshold sound-pressure levels for the TDH-39/MX41 AR earphone. p.1187-1188.[5J Michael, P, I.. and Bicnvenuc,GR A comparisan af acollstical performance between i new oncpiece earphone cushion and the conventianal two-piece MX-4l/AR cushion. J. Acoust. Soc.Amcr.67(2),1980.Pp.693~698.
[6l Robinson, DW A propasal far audiametric zera referrcd to the IFC. artificial car, UK Nationa!Physical I.abnratory.Acoustics Report Ac 85(1978).[7] Arlinger,$. Normal thresholds of hearing at prelerred frerjuencies, Scand. Aedial., ll, 1982,pp.285--286.
[&] Rasnussen,O. Reference equivalent threshold sound pressure levels for headphanes at orie-third octave standerd frequencies, Internal Report No. l4, lgsl, The Acoustics Laboralory, Technical University of Denmark, Lyngby.[g] Brinkmann,K, and Richier,U. Determination of the normal threshold of hearing by bone conduc-tion using different types of bone vibrators,Audiological Acaustics .22,1983,Pp, 62-- 85 and 114122,
[1oJ Benwell, DA and Hussey,RG Refercnce equivalent threshold sound pressure levcls at 5 andG. 3 kHz using telephonics TDH 3g earphones with MX-41/AR cushions ,J. Acoust. Soc. Amer.72,1982,Supplement 1.p. S. 109.[11]GB/T 3240:1982 Frequencies commonly used in acoustic measurements [127 GB/T7583.1987 Acoustics - Pure tone air conduction audiometry for hearing protection [13] GB/T7582,1987 Acoustics - Otology - Relationship between normal air conduction hearing threshold and age and gender [14] GB/T1854.3.1998 Acoustics - Reference zero level for calibration of audiometric equipment - Part 3: Bone vibrator pure tone reference equivalent threshold level Acoustic audiometry methods - Basic audiometry for pure tone air conduction and bone conduction [15] GB/T16403:1996threshold sound-pressure levels for the TDH-39/MX41 AR earphone.J. Acoust. Soc. Amer. .39,1966,Pp.1187-1188.[5J Michael, P, I.. and Bicnvenuc,GR A comparisan af acollstical performance between i new oncpiece earphone cushion and the conventianal two-piece MX-4l/AR cushion. J. Acoust. Soc.Amcr.67(2),1980.Pp.693~698.
[6l Robinson , DW A propasal far audiametric zera referrcd to the IFC. artificial car, UK Nationa!Physical I.abnratory.Acoustics Report Ac 85(1978).[7] Arlinger,$. Normal thresholds of hearing at prelerred frerjuencies, Scand. Aedial., ll, 1982, pp.285--286.
[&] Rasnussen,O. Reference equivalent threshold sound pressure levels for headphanes at orie-thirdoctave standerd frequencies, Internal Report No. l4, lgsl, The Acoustics Laboratory, Technical University of Denmark, Lyngby.[g] Brinkmann,K, and Richier,U. Determination of the normal threshold of hearing by bone conduc-tion using different types of bone vibrators,Audiological Acaustics .22,1983,Pp, 62 -- 85 and 114122,
[1oJ Benwell, DA and Hussey,RG Refercnce equivalent threshold sound pressure levcls at 5 andG. 3 kHz using telephonics TDH 3g earphones with MX-41/AR cushions ,J. Acoust. Soc. Amer.72,1982,Supplement 1.p. S. 109.[11]GB/T 3240:1982 Frequencies commonly used in acoustic measurements[127GB/T7583.1987 Acoustic pure tone air conduction audiometry for hearing protection [13] GB/T7582,1987 Acoustics - Otology - Relationship between air conduction hearing thresholds and age and gender in normal subjects [14] GB/T1854.3.1998 Acoustics - Calibration of audiometric equipment - Reference zero level - Part 3: Bone vibrator pure tone reference Equivalent threshold level acoustic audiometry method Pure tone air conduction and bone conduction listening Basic audiometry method [15] GB/T16403:1996threshold sound-pressure levels for the TDH-39/MX41 AR earphone.J. Acoust. Soc. Amer. .39,1966,Pp.1187-1188.[5J Michael, P, I.. and Bicnvenuc,GR A comparisan af acollstical performance between i new oncpiece earphone cushion and the conventianal two-piece MX-4l/AR cushion. J. Acoust. Soc.Amcr.67(2),1980.Pp.693~698.
[6l Robinson , DW A propasal far audiametric zera referrcd to the IFC. artificial car, UK Nationa!Physical I.abnratory.Acoustics Report Ac 85(1978).[7] Arlinger,$. Normal thresholds of hearing at prelerred frerjuencies, Scand. Aedial., ll, 1982, pp.285--286.
[&] Rasnussen,O. Reference equivalent threshold sound pressure levels for headphanes at orie-thirdoctave standerd frequencies, Internal Report No. l4, lgsl, The Acoustics Laboratory, Technical University of Denmark, Lyngby.[g] Brinkmann,K, and Richier,U. Determination of the normal threshold of hearing by bone conduc-tion using different types of bone vibrators,Audiological Acaustics .22,1983,Pp, 62 -- 85 and 114122,
[1oJ Benwell, DA and Hussey,RG Refercnce equivalent threshold sound pressure levcls at 5 andG. 3 kHz using telephonics TDH 3g earphones with MX-41/AR cushions ,J. Acoust. Soc. Amer.72,1982,Supplement 1.p. S. 109.[11]GB/T 3240:1982 Frequencies commonly used in acoustic measurements[127GB/T7583.1987 Acoustic pure tone air conduction audiometry for hearing protection [13] GB/T7582,1987 Acoustics - Otology - Relationship between air conduction hearing thresholds and age and gender in normal subjects [14] GB/T1854.3.1998 Acoustics - Calibration of audiometric equipment - Reference zero level - Part 3: Bone vibrator pure tone reference Equivalent threshold level acoustic audiometry method Pure tone air conduction and bone conduction listening Basic audiometry method [15] GB/T16403:1996
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