Acoustics-Reference zero for the calibration of audiometric equipment-Part 7：Reference threshold of hearing under free-field and diffuse-field listening conditions
Some standard content:
GB/T4854.7—1999
This standard specifies the reference audiometer for calibrating audiometric equipment for sound field audiometry: Sound field audiometry is a special case of equal loudness criteria. In academic standards, it originally followed the equal loudness line standard, namely the minimum audible field (MAF) in ISO226:1987 or GB/1963—1985. In order to serialize the zero-level hearing standards, JSO independently compiled MAF into a new standard, ISO389-7:1996. Due to the continuous improvement of audiometry methods, the MAF data of the new standard has been almost completely reorganized. Basic zero-level for calibrating audiometric equipment This standard is the seventh standard in the GB/T 4854 series, and is equivalent to ISO 389-7:1996 Acoustics Part 1: Basic hearing thresholds for free-field and extended-field audiometry. The zero-level GB/T 4851 series has 7 standards under the general title "Basic zero-level for calibrating audiometric equipment in acoustics": Basic zero-level for calibrating audiometric equipment 1. GB/T 4854.1 2. GB/T 16402 3. GB/T 4851. 3
4. GB/T 4854. 4
5. GH/T 4854. 5
6. GB/T 4854. 6
7. GB:T 4854. 7
Reference zero level for calibrating audiometric equipment
Reference equivalent threshold level of pure tones for bone vibrators
Reference zero level for calibrating audiometric equipment
Reference level of narrow-band masking noise
Reference zero level for calibrating audiometric equipment
Reference equivalent level of pure tones in the frequency range
Reference zero level for calibrating test equipment
Reference equivalent level of short-term test signalsReference audiometric tests for free-field and diffuse-field audiometry: GB/T 16492--1996 During the formulation period, the standard series was formed, so it is numbered as GB/T 13/T 485d series. When it is finalized, it will become GB/T 4854.3.
Appendix A and Appendix B of this standard are both informative appendices. This standard is proposed and managed by the National Technical Committee for Acoustic Standardization. The units that promote this standard are: Institute of Psychology, Chinese Academy of Sciences, Institute of Acoustics, Chinese Academy of Sciences. The main drafters of this standard are: Li Zhi, Zhang Jiayi. GB/T4854.7—1999
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 usually involves It is completed by ISO technical committees. Each member country has the right to participate in the technical committee when it is interested in a certain standard determined by the ISO technical committee. International organizations, both governmental and non-governmental, that have relations with ISO can also participate in this work: The International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) maintain close cooperation in all aspects of electrotechnical standardization. The draft international standards adopted by the technical committees shall be circulated to the members for voting. The draft international standards shall require at least 7% of the votes of the member countries to be published as international standards. International Standard ISO389-7 was drafted by the Basic Subcommittee of ISO/TC Acoustics. The first edition of IS389-7 includes some revisions to ISO226:1987 white field pure tone listening T (column 4 of Table 1) and Appendix A (minimum audible sound field curve) diffuse field 1/3 frequency band noise listening T\ (column 3 of Table 4) and the difference between these values (column 2 of Table 1+). The equal loudness contours included in ISO 2261 have recently been revised within ISO/TC 43 and are therefore not included in this part of ISO 389. Under the general title "Acoustics - Reference zero level for calibration of audiometric equipment", ISO 389 consists of the following parts: Part 1: Basic equivalent sound pressure level of pure tones of pressure-sensitive headphones; Part 2: Basic equivalent wide-band sound pressure level of pure tones of plug-in headphones; Part 3: Basic equivalent sound pressure level of pure tones of oscillators; Part 4: Basic level of narrow-band masking noise; Part 5: Basic equivalent sound pressure level of pure tones in the frequency range of 8 to 16 kHz; Part 6: Basic equivalent sound pressure level of short-term acoustic test signals; Part 7: Basic hearing distances for free-field and extended-field audiometry. Part 1 will be a re-issue of ISU389:1991. Appendices A and B of this standard are indicative and for reference only. GB/T 4854.7-1999
Each part of the G/T4854 series specifies a unique reference zero level for the calibration of audiometric equipment. (GB4854.1 and GB/T16402 use audiometric equipment that sends pure tones with H-type or insert earphones, respectively. The corresponding audiometric methods are in GB/T 1(:403 neutrons are specified.
In some audiology practices, it may be necessary to use a tester to send test signals in a free field or diffuse field. The corresponding audiometric method is also specified in 6B/T164C3. This standard specifies the reference audiometric equipment for calibrating audiometric equipment used for sound field audiometry. Hearing reading is similar to other subjective phenomena and varies slightly from person to person. However, for a group of normal otologists in a limited age range, the value that characterizes the central trend of the group can be determined. The reading values specified in this standard and other parts of the GB 4854 series are applicable to normal otologists within the age range of 18-25 years old. Compared with B1963, the age standard used is more Strict, so that the determined set of standards has a consistent relationship between hearing threshold and age.
The standards specified in this standard involve: bzxz.net
1) Listening to pure tone binaurally in a white plane traveling wave, the subject faces the sound source directly (normal incidence), the sound pressure level is measured at the center of the head of the subject in the free traveling wave without the listener,
2) Listening to 1/3 octave band (purple or pink) noise binaurally in a diffuse field, the sound pressure level is measured at the center of the head of the subject in the sound field without the listener:
For (white or pink) noise with frequencies above 8 Hz, each set of standards is equally applicable to any other frequency band when the bandwidth is less than the critical band.
The base is an estimate based on technical information from the most reliable data available from laboratories in several different countries. Appendix A gives notes on the derivation of the base values and the source of the data, and Appendix B lists references. 1 Scope
National Standard of the People's Republic of China
Acoustics--Reference zero
for the calibration of audiometric equipmcnt-Part 7: Reference threshold of hearing under free-fieldand diffuse-field listening conditions
Acoustics--Reference zero
for the calibration of audiometric equipmcnt-Part 7: Reference threshold of hearing under free-fieldand diffuse-field listening conditions This standard specifies the reference threshold of hearing for calibrating listening equipment under the following conditions of use: GB/T 4854.7-1999
eq1ISO 389-7:1996
a) The sound source when the listener is at a low level is a plane wave (outward field) or a diffuse field. If the sound source is a plane wave, the sound source is virtually in front of the listener (normal incidence).
Note 1: For the correction of the sound source when the selected sound incidence angle deviates from normal incidence for free-field listening, see GB/T 154C3,h) If it is a free field, the sound signal should be a pure (string) tone, and if it is a diffuse field, it should be /3 times the band (white or pink) noise. ) The sound pressure level should be measured at the center of the listener's head (the midpoint of the line connecting the two external auditory canal openings) when the listener is not present, and listen with both ears.
e) The sound pressure level corresponding to the tympanic hearing threshold is determined by the median value of the threshold of a group of appropriate number of listeners.) The listeners should be normal people with otolaryngology certification: aged 18~-25 years old. Note 2: The listening level of the listener derived from the reference set by this standard is 17 dB or less than 10 dB according to GB 4854.1. This is the difference between the selected standard and the standard derived from GB 4854.1. The determination of the listening level is determined by the up-down method and the double-up method specified in (B/T 16203). Table 1 lists the basic references of the common frequencies from 20 Hz to 16 kHz and the listening frequencies in the middle of the 1/3 octave band series specified in GB/T 324U in digital form, and is shown in Figure 5. It should be emphasized that the limit reference is different from the listening level specified in GB 4851.1 and (B/T 16402, because the latter belongs to the single-level audiometry with headphones, and its voltage level is related to the specified coupling cavity and .H simulator. Therefore, the basic reference of this standard is GB/T 4854.1.1 or GB/T1.6402 are not suitable for direct comparison. 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 revised, all versions are valid: All standards will be revised. The service provider using the vehicle standard should explore the possibility of using the latest version of the following standards. G/T 3210-192 Frequencies commonly used in audiometric testing (NEQ 150 266; 1975) GB/T 4854.11999 Acoustic calibration of audiometric equipment - Reference zero level - Part 1: Reference equivalent sound pressure level for on-ear headphones (EAVS 389-1: 1598)
GI/T 4963-1985 Standard equal loudness level for audiometric testing Approved by the State Administration of Quality and Technical Supervision on March 8, 1999 and implemented on September 1, 1999
GB/T 16402
GB/T 16403
3 Definitions
This standard adopts the following definitions
3.1 Hearing threshold
GB/T 4854.7 -1999
Pure tone reference equivalent threshold sound pressure level of earphones (e1S0389-21994) Audiometry method Basic audiometry for pure air conduction and bone conduction (eIS08253-1:1989) Under specified conditions, in repeated experiments with specified signals, the subjects can correctly distinguish the lowest sound pressure of the given signal with a certain percentage. The characteristics of the signal, the way it reaches the listener and the position where the sound pressure is measured must be explained: Note: Unless otherwise specified, the ambient noise reaching the human ear is considered to be negligible. It is generally expressed as a fraction relative to 20Pa. Repeated tests refer to the use of constant puncture method. Other physical methods can also be used, but the method used should be explained. 1 A certain percentage is 50%
3.2 Normal otology Atalogically normal pcrsun Normal health condition, no ear disease symptoms, no anal obstruction, no history of excessive noise exposure, no ototoxic drugs or family hearing loss.
3.3 Reference threshold uf hearing The sound pressure level of a specified frequency pure tone or 1/3 times the sound pressure level of the band noise, corresponding to the median value of binaural hearing of normal otology people aged 18 to 25 years old
Note: "Medium" or \median\ is a characteristic number with the most concentrated trend in statistics. It refers to the number in the middle when the data are arranged in order of size; if there are two, it is equal to the arithmetic mean of the two numbers. 3.4 Diffuse sound field The sound field with uniform density and random distribution between each diffusion patch. 4 Technical requirements
Table 1 lists the basic hearing test conditions specified in Chapter 1. The table also lists the differences between the sound pressure levels of the 1/3 octave band noise in the extended sensitivity field and the sound pressure levels of the pure tone in the normal incident free-wave. A diagram of the basic thresholds is shown in Figure 1.
Table 1 Differences between the reference hearing gap and the two sound fields for the audiometric equipment listed in Chapter 1 Basic
White field measurement
(normal incident)
TStandard 20 μPa)
Diffuse field audiometry
T:{Standard 20 μPa)
Difference ·
AL-TT
10 0c0
11 2(10)
*t.5 Approximate value link number
Free listening
(normal incidence)
GB/T 4854. 7—1999
Table 1 (end)
Basic listening
Field listening
Tr(reference 20 Fe)
T'reference 20 μPa)
The experimental data of Tr at 20 II Hz and L at 1G030 Hz are just the result of an experiment.
.--TI-T
GB/T 4854.7—1999
Frequency.H:
Free field scattered field
Figure 1 Basic listening of pure tone and expanded field binaural audiometry in white main field (normal incidence) [/3 times the frequency band noise oce
A1 Free field audiometry
GH/T 4854.71999
Appendix A
【(Informative Appendix)
Notes on the Calculation of Reference Audio
GB1854.1 The reference audio frequency for white-field audiometry is currently determined by the Internet. The results of 7 independent experimental studies submitted to 150/[(43) are shown in Appendix 0. The reference audio frequency in the second column of Table 1 is derived from the smooth curve that best fits all experimental data calculated by the least squares law. The frequency used is 800Hz and above. The frequency below 800Hz is a 4th order polynomial relationship, and the frequency above 800Hz is a 12th order polynomial relationship. Both frequency and sound pressure level are logarithmic. The 1/3 times the common frequency and the audiometric frequency in between are calculated from the polynomial relationship: the experimental data used in the calculation process are neither weighted for the difference between the experimental subject's hearing level and dB as in audiometry, nor for the number of experimental subjects: Figure A] is a data fitting curve from references [] to [7. 1o
Frequency.H:
Example:
Reference [1
Reference 2]
Oral E3
■ Reference [}]
Reference L5]
Table Reference [6]
Reference [?-
The best fitting curve derived from the experimental data of the standard hearing threshold of field audiometry Table A1
Reference
Number of test subjects
Age of test subjects
Average, Hz
Research on the standard hearing threshold of field audiometry (reference technical guidance) E2.
34~42*
15~·44
19--25
21~-25
18--25
11 205
References
Number of Experimenters
Variable Test Subjects
Subjects
Hearing Width Level
Used
34~428
CB/T4854.7—1999
Table A1 (Complete)
15~44)
21~-25
Any Frequency below 8 000 Hz
1) Below 1000 Hz 120 subjects.
2) Above 1000 Hz Average Age of Subjects No age effect was found at low frequencies. 3) Effect of frequency
A2 Diffuse-field audiometry
16 000
18--30
The difference between the free-field and diffuse-field audiometry reference values was obtained from 9 independent experimental studies, some of which were obtained from the literature and some were submitted directly to IS0/TC 43.
Note: See references [8]--[15] in Appendix D. Brief characteristics of these experiments are as follows:
Reference [8]: Loudness comparison of 5 subjects: simulated diffuse field vs. white field. Reference 97: Probe measurement of two types of sound fields, 6 subjects, diffuse field in reverberation chamber. GB/T 4854.7-1999
Reference 210: a) Objective measurement: Response of the human ear in natural and diffuse fields; 20 subjects; Probe transducer: diffuse field generated in reverberation chamber.
b) Subjective measurement: Loudness comparison of 26 subjects: simulated diffuse field vs. white field. Reference L117:Determine the difference between the 20phon and 20phan equal loudness lines in free field and diffuse field; 12 subjects Reference [127: Measure the response of 7 replicas of the human ear in diffuse field and diffuse field, Reference [13]: Diffuse field probe measurement of tympanic membrane deformation; 16 subjects, diffuse field; These data, together with the free field tympanic membrane deformation data of reference [12], are used to calculate the △ value. Reference [14: Measure the impulse response of the human ear in free field using the maximum sequence method: 37 sound incidence directions; Probe microphone: 12 subjects: Calculate the diffuse field sensitivity from the directivity. Reference [15]: Measure the impulse response of the human ear in free field using the maximum sequence method: 97 sound incidence directions, Probe microphone: 140 subjects; Calculate the diffuse field characteristics from the directivity. Determine the 11th order polynomial relationship that best fits the experimental data, and calculate the △ value for the 1/3 octave common frequency and the middle listening frequency from this relationship.
Figure A2 is the data and fitting curve of reference [8]~151. The diffusion field reference data (Table 1, T,) are calculated by subtracting the above value from the free field data, 10
: 0000
Legend:
D Reference [a
a Reference [9]
Reference [10]
. Reference [11]
Reference [2?
■Reference [13]
+Reference [?4]
Reference L:5]
Figure A2 The best fit curve of △L and these data specified in Table 1 is derived GB/T 4854.7-1999
Appendix B
(Record of prompts)
References
[IJROBINSON, L). W. DADSON: R. $. A re-determinatian of the qual loudress relatiuns fu.pure-tones.Br.Jaurn. App.Phys.,7,i956,pp.166-~181.21 BRINKMANN, K. Audiorcter Bezugsschwclle und Freifeld Horschwelle Aruslica, 28, l973.PP. L17-~154.
L3_ BETKE. K., MELLERT, V, New measurements of equal-loudness level contours., Proc. InttInoise 82, Newport Beach. USA, Pp, 753--796.ISJZUKI.S.,SUZUKI,Y.,SHUNICHI,K.,SONE,T.,KUMAGAI,M.,MIURA.H.,K AD), II, Egual loudness level contours for pure-tones unrler free-field listening conditions(l): Some data rnd considcrations un experirnenital cunditions, J. Aroust. Sor. Jpil. (E), 10.1989, pp, 329--338.
L5] FASTI..H., JAROSZEWSKI, A., SCHCRER, E.,ZWIGKER, E. Equal loudness contoursbetween 100 and 1 000 Hz for 30. 50 and 70 phon. Acustica, 70, 1900, pp. 197-~201[6J VORLANDER,M. Freifeld-IIorschwellen von 8--16 kHz. Fortschrille der Akt.suk,DAGA'gl.BadHonnef .PG-GrrbH,199l,pp.533~536. WATANABE, T.. Mgl.LER. H. Iearing threshold end cqual louduess coniours in frce Held alfrcqucncies below J kHz. T., MigLLER. H. Low frequency hearing thresholds in picssure field und in frer field, J.Low Frequcney Noisc Vibr., 9, 1990, pp. l06~-115.[SJ KUHl., W,, WESTPHALW. , Pp. 407-c8.[g JAHN. 7s---8l.[ioJROBINSON,DW,WHITTI.b,L..S.BOWSIIER.JM Flsevier,Amisterdam, 961, pp. 63~-78. Baltimore,1980,pp,106--124.
[13I KILLION, MG . lERGER, FH NlJSS. RA Difuse field response of the ear. J. A-coust. Soc. Am. , 81 (Suppl.1). 1987, p, 75. Aruztica. Fl.1990, pp, 257-~268.
I5J HAMMERSHOI, D. MOLLER, H, , SORENSEN, MF, I.ARSHN. K. A,Iead-relatedTranslrr Fun:lians: Reference on 10 Iluman Subjceis. Prpt. 92nd Audio Eng. Soc. Con-vention. Vienna. 1992. Preprint 3289. Abstract in: J. Audin Eng- Soc. , 10, 1932. P. 443._16JGB/T49631985
Standard equal loudness contours of pure tone in Xiaoyou field
[17GE/T 4854.11999Acoustic cross-reference audiometric equipment basic level Part 1: Compressed H type H machine pure tone equivalent threshold sound positive level
-18JGB/T 16402
F191GB/I 4854. 3
207GB/T16103-1595
Base zero level for calibration of audiometric equipment for pure tone and equivalent tothrottle level of plug-in earphones Part 3: Bone grip audiometric method for pure tone air conduction and bone conduction audiometry Basic audiometry method
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