Methods for the Measurement of Insertion Loss of Hearing Protection Devices in Continuous or Impulsive Noise Using Microphone-in-Real-Ear or Acoustic Test Fixture Procedures
This standard provides methods for the measurement of the insertion loss of hearing protectiondevices in specified continuous and impulsive noise environments. The microphone-in-real-ear(MIRE) method utilizes human test subjects and may be used for hearing protectors that enclose theears and make supra-aural or circumaural contact with the head, whereas the acoustical test fixture(ATF) method employs an inanimate fixture and can be used for any hearing protection device. Thestandard contains information on instrumentation, calibration, and electroacoustic requirementsincluding details regarding the sound field of test facilities, the acoustical characteristics of ATFs, andsubject selection and training and location of ear-mounted microphones for MIRE testing. Methods formeasuring or determining sound pressure levels in the ear are also specified as well as methods forreporting the calculated insertion loss.
ANSI/ASA S12.13 TR-2002 (R2010)
ANSI Technical Report Evaluating the Effectiveness of Hearing Conservation Programs through Audiometric Data Base Analysis.
This ANSI Technical Report describes methods for evaluating the effectiveness of hearing conservation programs in preventing occupational noise-induced hearing loss by using techniques for audiometric data base analysis. The rationale is given for using the variability of threshold measurements in annual monitoring audiograms as the basis for judging effectiveness. Guidelines are discussed concerning how to select a restricted data base to which the analysis procedures will be applied. Specific procedures for data analysis are defined, and criterion ranges are given for classifying program effectiveness as acceptable, marginal, or unacceptable. Sample results for industrial audiometric data bases contributed to Working Group S12/WG12 are included as an annex for reference and illustration.
Methods for Measuring the Real-Ear Attenuation of Hearing Protectors
Specifies laboratory-based procedures for measuring, analyzing & reporting passive noise-reducing capabilities of hearing protection devices. The procedures consist of psychophysical tests conducted on human subjects to determine real-ear attenuation measured at hearing threshold. Two fitting procedures are provided: Method A-trained subject fit and Method B-inexperienced subject fit, intended to approximate protection that can be attained by groups of informed users in workplace hearing conservation programs.
Hearing Loss Prevention for Construction and Demolition Workers
This standard applies to all construction and demolition workers with potential noise exposures (continuous, intermittent and impulse) of 85 dBA and above. This standard is intended to help employers prevent occupational hearing loss among construction and demolition workers.
Acoustics - Hearing protectors - Part 1: Subjective method for the measurement of sound attenuation
Specifies a method for measuring sound attenuation at the threshold of hearing. The procedure is designed to yield values close to the maximum attenuation which are not normally attained under field conditions. The values reflect the attenuating characteristics only to the extent that users wear the device in the same manner as did the test subjects. Data are collected at low sound pressure levels but which are also representative of the values at higher sound pressure levels.
Acoustics - Hearing protectors - Part 2: Estimation of effective A-weighted sound pressure levels when hearing protectors are worn
Describes three methods (the octave-band, HML and SNR methods) for estimating the A-weighted sound pressure levels effective when hearing protectors are worn. The methods are applicable to either the sound pressure level or the equivalent continuous sound pressure level of the noise. Although primarily intended for steady noise exposures, the methods are also applicable to noises containing impulsive components. They are not suitable for use with peak sound pressure level measurements.
This standard is also available from:
ISO Corrigendum 2006 /
DIN Corrigendum 2007 /
SS Corrigendum 2007
Acoustics - Hearing protectors - Part 3: Measurement of insertion loss of ear-muff type protectors using an acoustic test fixture
ISO 4869-3:2007 specifies a method for measuring the insertion loss of ear-muff type hearing protectors using an acoustic test fixture. The method is applicable to the investigation of production spreads of performance as part of type approval or certification procedures, and to the investigation of the change of performance with age. It is intended to ensure that ear-muff hearing protector samples submitted for subjective testing of attenuation according to ISO 4869-1 have performances typical of the type. The method specified in ISO 4869-3:2007 is not applicable as the basic test for type approval. Performance data obtained by this method are not intended to be quoted as representing the real-ear sound attenuation of an ear-muff, nor the protection provided by the ear-muff.
This standard is also available from:
Acoustics - Hearing protectors - Part 5: Method for estimation of noise reduction using fitting by inexperienced test subjects
ISO/TS 4869-5:2006 specifies a method for measuring noise reduction of passive hearing protectors at the threshold of hearing. The method is designed to provide estimates of the noise reduction obtained by typical groups of users in real-world occupational settings, who may lack the training and motivation to wear hearing protectors in an optimum manner. The principle of the test method is to measure the difference in hearing threshold with and without wearing a hearing protector. This difference between the thresholds constitutes the noise reduction. The measurement is done twice on a given number of test subjects. This test method yields data that are collected at low sound pressure levels (close to the threshold of hearing), but which are also representative of the noise reduction values of hearing protectors at higher sound pressure levels. ISO/TS 4869-5:2006 is inapplicable for level-dependent hearing protectors for sound pressure levels above the point at which their level-dependent characteristics become effective.
This standard is also available from:
Guide to noise and vibration control on construction, demolition and maintenance sites (FOREIGN STANDARD)
Occupational noise management - Hearing protector program (FOREIGN STANDARD)
Specifies administrative responsibilities associated with a hearing protector program; the selection, use and maintenance of various types of hearing protectors; and training and motivation in regard to hearing protector programs.
Z94.2-14 - Hearing protection devices - Performance, selection, care, and use
Preface This is the seventh edition of CSA Z94.2, Hearing protection devices - Performance, selection, care, and use. It supersedes previous editions published in 2002, 1994, 1984, 1979, 1974, and 1965. This edition expands on performance requirements and the rating schemes that might help the user select hearing protection devices. It now includes the widely used noise reduction rating (NRR) and an applicable derating scheme. This edition no longer includes physical performance and related testing requirements (such performance is no longer sought by Canadian users). It addresses acoustical performance measurements and includes revisions in the packaging marking requirements to clarify the use of the various ratings. Clauses 8 to 12 regarding the selection, care, and use of hearing protection devices (HPDs) have been expanded to include issues related to style and functions of hearing protectors not mentioned in previous editions, as well as the potential use of field attenuation estimation systems (FAES). Table 4, which specifies the selection of HPDs based on noise exposure levels, now requires octave-band noise measurements at exposures greater than 105 dBA. Although users of hearing protection devices are required to follow the criteria in Clauses 8 to 12 in order to comply with this Standard, reference should also be made to applicable local occupational health and safety regulations, which can require additional or superior performance. The CSA Subcommittee on Hearing Protection recognizes that significant variations in performance (as great as ▒ 20 dB attenuation) can occur depending on how an HPD is used. This Standard emphasizes the importance of a comprehensive hearing loss prevention program, including hazard assessment and instruction on the careful selection, proper wearing, and high-quality maintenance of hearing protection devices. It is the opinion of the Subcommittee that wearing HPDs without proper selection, care, and use can result in significantly lower attenuation for the user than that obtained from the tests specified in this Standard. This Standard should be used in conjunction with CSA Z1007, Management of hearing loss prevention programs, which is currently under development. CSA Z1007 covers all aspects of the creation and management of hearing loss prevention programs. CSA gratefully acknowledges the financial and in-kind support from the Canadian government departments responsible for occupational health and safety for the development of this edition of the Standard. Introduction This Standard deals with hearing protection devices (HPDs). They are used to reduce the noise level that reaches the ear of noise-exposed people and to reduce the annoyance and/or hazard of noise exposure. Of the many characteristics of HPDs, such as attenuation, comfort, and communication ability, this Standard focuses on attenuation. It specifies two methods of measuring the real-ear attenuation provided by HPDs and outlines how to use the results to estimate the sound levels reaching the protected ear. Several procedures for estimation of protected levels while wearing HPDs of varying accuracy and complexity are included in this Standard. The user may decide which one to use. Other related issues such as fit, care, use, overprotection, selection, and training are also addressed. The companion Standard, CSA Z1007, contains more detailed information. CSA Z1007 covers the use of HPDs as part of a comprehensive hearing loss prevention program. Scope 1.1 Clauses 4 to 7 cover performance, acoustical testing, and packaging requirements for personal hearing protection devices (HPDs). Clauses 8 to 12 cover the selection, care, and use of HPDs, which will contribute to an effective hearing loss prevention program. 1.2 The following types of HPDs are covered in this Standard: a) earplugs (including semi-inserts); b) earmuffs; and c) helmets, with or without electronic communication capabilities. 1.3 In this Standard, shall is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; should is used to express a recommendation or that which is advised but not required; and may is used to express an option or that which is permissible within the limits of the standard. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.