This standard specifies the calculation method for permanent hearing threshold changes caused by different noise exposure levels and exposure time for adult population, and evaluates the risk rate of hearing damage caused by daily repetitive noise exposure. This standard applies to audio-frequency noise with steady, intermittent, fluctuating, irregular or pulse characteristics. For transient sound pressure levels exceeding 140dB and higher sound pressure, this standard can be used for extrapolation. GB/T 14366-1993 Acoustic occupational noise measurement and noise-induced hearing damage evaluation GB/T14366-1993 Standard download decompression password: www.bzxz.net
This standard specifies the calculation method for permanent hearing threshold changes caused by different noise exposure levels and exposure time for adult population, and evaluates the risk rate of hearing damage caused by daily repetitive noise exposure. This standard applies to audio-frequency noise with steady, intermittent, fluctuating, irregular or pulse characteristics. For transient sound pressure levels exceeding 140dB and higher sound pressure, this standard can be used for extrapolation.

National Standard of the People's Republic of China
Acoustics-Determination of occupatioual noisetxpnsure and estimation of noise-inducedhearing impairment
CB/T14366-93
This standard is equivalent to the international standard [S01999-1990 Acoustics-Determination of occupatioual noisetxpnsure and estimation of noise-inducedhearing impairment]. This standard is an evaluation of the "permanent hearing loss changes" (VIFTS) caused by occupational noise exposure and people of different ages, and a general prediction method for occupational hearing loss.
1 Subject content and scope of application
1.1 This standard specifies the calculation method for permanent hearing value changes caused by different noise exposure levels and exposure times in adult populations, and evaluates the risk rate of hearing loss caused by repeated noise exposure. 1.2 When the value of the hearing loss with the audiometric frequency or the combination of these frequencies exceeds a certain value, this standard provides several formulas for calculating the basis for hearing impairment.
1-3 The hazardous noise exposure acting on the population is measured by the average A-level sound exposure level (integrated by the pressure square over time) F4 and the relevant coefficient of the average working H (set as 8h) within the specified exposure period. 1.4 This standard is applicable to the city frequency (less than 10kIIz) noise with steady, intermittent, fluctuating, irregular or pulse characteristics. For transient sound pressure levels exceeding 140dB (the reference sound pressure level is 20uPa) and higher, this standard can be extrapolated. 1.5 The calculation formula for evaluating hearing loss N1TPS caused by noise exposure is given. The minimum frequency of the measured hearing is 0.5 to 6kH. The average noise exposure level for 8h per day is 3.64× 10g～1.15×105Pa2·(i.e. 75-~100dB), exposure time is 0 to 40 years, and the median value of NIPTS and the statistical distribution above or below the median value within the range of 0.05 to 0.95 are specified in detail. It is the same for male and female groups. Method: D Although the HIPTS data of this standard are taken from the occupational noise exposure screening population, it can also be tentatively used to estimate the impact caused by comparable non-occupational comprehensive noise exposure (working time should be noted). Because noise-induced hearing loss is not only the result of exposure to occupational noise, but also the result of the total amount of noise, it is also important to fully estimate non-occupational noise exposure (for example: commuting, at home and in entertainment venues). Only when This standard is only effective for predicting hearing loss from occupational noise exposure when occupational noise exposure is negligible. Otherwise, the calculated result should be the total of each noise level (including occupational and non-occupational noise). If necessary, the proportion of occupational noise exposure to total hearing loss can also be estimated. ② This standard is a prediction method based on broadband steady-state non-modulated noise data. It can be temporarily used for modulated noise or impulse noise. It can be considered that when steady-state noise is higher than modulated noise or impulse noise SdB, the degree of noise hazard is basically the same. 1.6 is to calculate the hearing threshold and the risk rate of permanent hearing loss or damage caused by noise exposure. The hearing of non-noise-exposed people of comparable age must be known. In order to facilitate users to apply For different purposes, this standard allows the use of two different data sources as the hearing thresholds of non-noise-exposed populations.
: Normal otological population, that is, the highly screened population according to the national standard G[37582--87 Relationship between the air conduction hearing valve and age and gender of normal otological people\, see 5.2.1 database A of this standard. b. Other populations that are considered appropriate can be selected, see 5.2.3 database B of this standard. Note: All the data and methods listed in the standard are approximate values ​​generated based on carefully simplified experimental data. In this way, the validity of the standard is limited to the existing range of variables, quantiles and noise exposure. This standard is based on statistical data, so it does not use "prediction or evaluation of personal hearing loss or hearing impairment." Appendix A: According to GB7582-87, a method for calculating the hearing threshold of the normal otological population (highly screened) related to age is given. Appendix B: A method for calculating the hearing threshold of the unscreened population in a typical industrial country is given. Appendix C: An example of the selection of the hearing threshold of a specific "unscreened population" is given. When the method in this standard is used, the result is almost the same as the hearing impairment predicted by ISO1999 (Edition 1). Appendix D: An example of using this standard to evaluate the risk rate of hearing loss is given. Appendix E: A table shows the calculated functional relationship between the NIPTS value at 6 frequencies, 3 quantiles and the exposure time, daily A-weighted sound exposure. Among them, the exposure time (10, 20, 30, 40 years), daily A-weighted sound exposure (8.64×10*, 1.15×10°3.64×10 and 1.15×105Pa2) or the equivalent continuous A sound level (85, 90 , 95.100dH), 6 frequencies (0.5, 1, 2, 3.4 and 6kHz); 3 percentiles (0.1, 0.5, 0.9). 2 Reference standards
GB4854 Standard zero level for calibration of pure tone audiometers GB7583 Acoustic pure tone air conduction audiometer for hearing protection GB7582 Acoustic otology Relationship between normal air conduction hearing and age and gender GB8785 Electrical and acoustic properties and test methods of sound level GB3222 Method for measuring urban environmental noise wwW.bzxz.Net
GH3238 Acoustic single value and its reference value
3 Definitions
3.1 Sound pressure level, L: The unit of sound pressure level is decibel (dB), expressed by formula (1): L = 10 1g(p/pg)3
Where: p--sound pressure, Pa, according to GB3238, the reference sound pressure p is 20μPa. 3.2A-weighted sound pressure level, Lm: sound pressure level measured with frequency weighting A, in decibels (dB), can be obtained by formula (2), Z = 10 lg(pa/pa)
where a→—weighted sound H.Pa.
3.3A-weighted sound exposure level, Ea.7: The time integral value of the square of the A-weighted sound pressure in a certain time interval T, expressed in Pascal half-square second (Pa\·s), the A-weighted sound pressure can be obtained by formula (3): Ea.
where: (t)—the instantaneous A-weighted sound pressure of the sound signal integrated in the time interval T from to t. (3)
The time interval T\ is in seconds, which should usually include a full day of occupational noise exposure (generally 8h, or 28800s) or longer time, such as a work week.
Note, the sound exposure level, LEA,: the unit is decibel (dB), expressed by formula (4): Ier. lolg(Ea.r/E,)
where, EX10\P·*
② The noise exposure level normalized to the rated 8-hour T working day is obtained when —1.15×10-Pa·, which is 44.5dB smaller than k4,1 (see 3.6)
3.4day A-weighted sound exposure level, expressed in Pascal square seconds (Pa·). Note: If it is required to take note of non-occupational noise, the total A-weighted sound exposure level is the sum of the corresponding noise components in occupational noise and non-occupational noise.
3.5 Equivalent continuous A-weighted sound level, Lng.T: The unit of this sound level is decibel (dB), which can be calculated using formula (5): GB/T14366-93
LAn-T = 10lg[, -,
Where, t一t,=T, the average value is taken in the interval T to t. (pA()/pa)'de
Note: The time (1-=> used for direct measurement or calculation of Ag. should be able to reflect the results of the entire interval. For continuous noise and constant sound level LAm+, its numerical value is equal to L.-)
3.6 According to the standardization of the noise burst level of 8-hour working day, Lcx,9h This noise level is expressed in decibels (dB) and can be calculated using formula (6): Lex.ah = Laqt, + lolg(T./T,)武-
Effective duration of working day:
T basic duration (equal to nominal hours).
If the effective working day lasts for 8 hours and T, does not exceed 8 hours, then Lex.n is numerically equal to Ln.ib Note: The standardization of the noise burst level Lrx->
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