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1、BRITISH STANDARD BS 5330:1976 Method of test for Estimating the risk of hearing handicap due to noise exposure UDC 614 872.4:534.08 Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 13:58:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5330:1976 This British Standard, having been prepared unde
2、r the direction of the Engineering Divisional Council, was published under the authority of the Executive Board on 30 July 1976 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference E/1/3 Draft for comment 74/27161 DC ISBN 0 580 09481 2 Cooperating organiz
3、ations The Acoustics Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government department and scientific and industrial organizations: Association of Consulting Engineers British Broadcasting Corporation British Kinematograph Sou
4、nd and Television Society British Radio Equipment Manufacturers Association Cinematograph Exhibitors Association of Great Britain and Ireland Department of Industry National Physical Laboratory* Engineering Equipment Users Association Incorporated Association of Architects and Surveyors Institute of
5、 Acoustics Institute of Physics Institute of Sound and Vibration Research* Institution of Electronic and Radio Engineers Institution of Mechanical Engineers Institution of Municipal Engineers* Post Office* Royal Institute of British Architects Society of British Aerospace Companies Transmission Dist
6、ributors Association (BEAMA) The Government department and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the Committee entrusted with the preparation of this British Standard: British Airways Overseas Divi
7、sion British Internal Combustion Engine Manufacturers Association British Internal Combustion Engine Research Institute British Gas Corporation British Medical Association British Occupational Hygiene Society Department of the Environment Drop Forging Association Electrical Supply Industry in Englan
8、d and Wales Environmental Health Offices Association Health and Safety Executive London Transport Executive Medical Research Council Ministry of Defence National Association of Drop Forgers and Stampers National Coal Board Oil Companies Materials Association Amendments issued since publication Amd.
9、No.Date of issueComments Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 13:58:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5330:1976 BSI 09-1999i Contents Page Cooperating organizationsInside front cover Forewordii 1Scope1 2References1 3Definitions1 4Noise measurement1 5Calculation of ha
10、ndicap percentage from noise exposure2 6Hearing deterioration from causes other than noise4 Appendix A Direct measurement of equivalent continuous sound level7 Appendix B Bibliography7 Table 1 Partial noise exposure indices for sound levels from 80 dB(A) to 120 dB(A) and durations from 2 min to 10 h
11、 per day3 Table 2 Relation between composite noise exposure index and equivalent continuous sound level4 Table 3 Derivation of noise immission level from equivalent continuous sound level and duration of exposure5 Table 4 Percentage of persons attaining or exceeding a mean hearing level of 30 dB (me
12、an of 1 kHz, 2 kHz and 3 kHz)6 Publications referred toInside back cover Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 13:58:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5330:1976 ii BSI 09-1999 Foreword This British Standard has been prepared under the authority of the Engineering Divi
13、sional Council. In 1971 ISO/R 19991) was published, but since the preparation of that ISO Recommendation further work on this subject has been done, and the results of some of this work are reflected in this standard. This standard therefore differs substantially from ISO 1999 and has been submitted
14、 to the ISO Committee as a UK proposal for the revision of that standard. Persons regularly exposed to noise can develop hearing loss of such severity that their appreciation of music, perception of everyday acoustic signals or understanding of speech may be impaired. Hearing handicap, as understood
15、 in this standard, is impairment of understanding of conversational speech in low levels of background noise, and can be inferred from the shift in hearing threshold level. This standard is based on data which give, in statistical terms, the relation between different noise exposures and the permane
16、nt noise-induced threshold shift in people of various ages. These data apply to persons free from auditory impairment other than that due to noise (with allowance for the effects of age) and having substantially similar hearing levels in both ears. The risk of sustaining hearing handicap is estimate
17、d in terms of the handicap percentage. This is the percentage of noise-exposed persons attaining or exceeding a particular average hearing threshold level at which a hearing handicap is deemed to exist. Noise exposure is quantified in terms of the noise immission. The handicap percentage is tabulate
18、d for different noise immission levels and ages. Since this standard is based on statistical data it cannot be expected to provide an accurate assessment of hearing handicap due to noise exposure in individual persons. Determination of a maximum tolerable noise exposure is outside the scope of this
19、standard; it involves consideration of risk in relation to other factors. For occupational noise exposure such a limit is specified in the Department of Employment (HMSO, 1972) Code of Practice for Reducing Exposure of Employed Persons to Noise. A British Standard does not purport to include all the
20、 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 from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii,
21、pages 1 to 8, 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 table on the inside front cover. 1) Subsequently reissued as International Standard ISO 1999:1975. Licensed Copy:
22、 sheffieldun sheffieldun, na, Fri Dec 01 13:58:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5330:1976 BSI 09-19991 1 Scope This British Standard specifies a relationship between noise exposure and the expected incidence of hearing handicap. A handicap is deemed to exist when the average hearing
23、threshold level at 1 kHz, 2 kHz and 3 kHz attains or exceeds a certain value. The measure of noise exposure is derived from the equivalent continuous A-weighted sound level during one working day (assumed to be of duration 8 h), and expressed as a noise immission level for a given number of years of
24、 exposure. This British Standard applies to noise which is steady, intermittent, fluctuating or impulsive in character. In the case of impulsive noise this standard is not applicable where the instantaneous sound pressure exceeds 600 Pa 150 dB relative to 20 4Pa at any time during the exposure. Meth
25、ods for the determination of equivalent continuous sound level are given in clause 5. NOTEThe frequency combination of 1 kHz, 2 kHz and 3 kHz is in conformity with Department of Health and Social Security (1973), Occupational deafness: Report by the Industrial Injuries Advisory Council (Cmnd 5461, H
26、MSO). Other frequency combinations such as 0.5 kHz, 1 kHz and 2 kHz have been advocated elsewhere for the same purpose without clearly demonstrable superiority. It should also be noted that the hearing level of 50 dB referred to in the DHSS report corresponds to a 20 % disablement and differs from t
27、he criterion used in this standard for the minimum hearing level at which hearing handicap is considered to begin. 2 References The titles of the publications referred to in this standard are listed on the inside back cover. 3 Definitions For the purposes of this British Standard the following defin
28、itions apply. 3.1 partial noise exposure index an index determined by a sound level and its duration within a working day of 8 h (symbol Ei) 3.2 composite noise exposure index the sum of partial noise exposure indices for all relevant sound levels over a working day of 8 h 3.3 equivalent continuous
29、sound level that sound level in dB(A) which, if present for 8 h per day, produces the same composite noise exposure index as the various measured sound levels over one day (symbol Leq) 3.4 noise immission an index of the total energy incident on the ear over a specified period of time. Noise immissi
30、on level (NIL) is the A-weighted noise immission defined as follows: 3.5 permanent impairment of hearing for conversational speech due only to the effects of noise and age the hearing of a person is deemed to be impaired sufficiently to cause a handicap if the arithmetic average of the hearing thres
31、hold levels, of the two ears combined, at 1 kHz, 2 kHz and 3 kHz is equal to or greater than 30 dB referred to the audiometric zero of BS 2497-1, BS 2497-2 and BS 2497-3 3.6 handicap percentage the percentage of persons in a population attaining or exceeding the 30 dB average hearing threshold level
32、 described in 3.5, where age and noise exposure are the causative factors and no pathological condition is involved. The definition assumes that the hearing levels in the two ears are substantially similar 4 Noise measurement 4.1 General. Noise measurements shall be made with the A-weighting and exp
33、ressed in dB(A). The measurement locations and the length of time for which measurements are made shall be chosen so as to represent adequately the noise experienced in a typical day by the persons at risk. The method of noise measurement shall be selected from the procedures described in 4.2 and 4.
34、3, according to the nature of the noise. The method described in 4.3.1 is always applicable but the methods described in 4.2, 4.3.2.1 and 4.3.2.2, which allow the use of simpler equipment, are appropriate in many cases. NIL = Leq+ 10 log10 (T/T0) where Leqis the equivalent continuous sound level in
35、dB(A) Tis the duration of the exposure expressed in calendar years T0is one calendar year NOTEA typical calendar year is assumed to comprise 2 000 h of actual noise exposure. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 13:58:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5330:1976 2 BSI
36、 09-1999 4.2 Measurement of steady noise. If the noise is such that the fluctuations in level are small (see note 1), and if the average level over a short period (e.g. several seconds or minutes) is typical of that over a whole day, a sound level meter or equivalent shall be used to measure the noi
37、se. The sound level meter shall be set to A-weighting and “slow” response and shall comply with the requirements of BS 4197. If other equipment is used it shall have an overall performance which complies with these requirements. NOTE 1The noise may be deemed steady if the meter fluctuations lie with
38、in a range of 4 dB, the mid-point of this range being taken to define the average level for the purposes of this clause. NOTE 2The indicated reading of the meter is numerically equal to the equivalent continuous sound level Leq for an 8 h day. 4.3 Measurement of fluctuating, irregular, intermittent
39、and impulsive noise 4.3.1 Noises which fluctuate over a wide range of levels, and/or have an irregular time characteristic, including an impulsive characteristic, shall be measured by an integrating meter conforming to Appendix A. NOTE 1For noises with strong impulsive characteristics it is essentia
40、l that the dynamic range of the instrument be such as to avoid the instrument being overloaded by the peak sound pressure of the impulses. NOTE 2Miniature dose meters designed to perform the integration described in Appendix A may be used provided the dynamic range and signal/circuit noise ratio are
41、 adequate. The dynamic range is likely to be more restricted than in the case of meters designed for direct measurement of equivalent continuous sound level. The equivalent continuous sound level is obtained from the dose meter reading by calculation and by reference to the dosage calibration of the
42、 dose meter. 4.3.2 Other methods of measurement as described in 4.3.2.1 and 4.3.2.2 may be used in appropriate cases. These methods are not appropriate for noise with impulsive characteristics. The method in 4.3.2.1 is not appropriate when the time pattern is very irregular. 4.3.2.1 Steady noise wit
43、h stepwise variations in level If the noise varies among a few clearly distinguishable levels, the separate levels and durations shall be measured in accordance with 4.2 and the values used to derive the equivalent continuous sound level in accordance with 5.1.3. 4.3.2.2 Intermittent noise or noise
44、which varies in level from time to time (fluctuating noise). A statistical analysis of the noise levels over a typical period shall be made with automatic recording equipment having an overall performance equivalent to that of a precision sound level meter used under similar conditions. The noise le
45、vels shall be grouped into classes with a width of 5 dB, 2.5 dB or 1 dB as appropriate and the total duration within a day shall be recorded for each class. The equivalent continuous noise level shall be derived in accordance with 5.1.4. 5 Calculation of handicap percentage from noise exposure This
46、procedure is described separately for continuous, and for intermittent or fluctuating noise. 5.1 Derivation of equivalent continuous sound level 5.1.1 For steady noise of nominal duration 8 h per working day the level shall be read with a meter as described in 4.2. The equivalent continuous sound le
47、vel is then numerically equal to this reading. 5.1.2 Measurements made in accordance with 4.3.1 yield the value of Leq directly. 5.1.3 For intermittent sounds or steady sounds with stepwise variations measured in accordance with 4.3.2.1. Step 1. The total duration during one day of each sound level
48、is entered in the first column of Table 1 and the partial noise exposure index read at the intersection with the appropriate sound level. If the total daily duration is less than 2 min, the minimum value of 2 min should be used. Step 2. The arithmetic sum of the partial noise exposure indices obtain
49、ed in this way is the composite noise exposure index. Step 3. This value of the composite noise exposure index is entered in Table 2 and the equivalent continuous sound level is read off. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 13:58:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5330:1976 BSI 09-19993 Table 1 Partial noise exposure indices for sound levels from 80 dB(A) to 120 dB(A) and durations from 2 min to 10 h per day Duration per day Sound level in dB(A) 80828486889092949698100102104106108110112114116118120 h min 2 2.5 3 3.5 4 4.5 5 6 7
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