Audiometric Calibration and Standards: Calibration Equipment
Standards exist describing various different ear/mastoid simulators used for the calibration of audiometers. In order to bring together all acoustic measuring devices concerned with audiometric measurement, a new series of standards has been introduced based on IEC 60318 Electroacoustics - Simulators of human head and ear.
The reference coupler (IEC 60318-3) and the artificial ear (IEC 60318-1) are used for the calibration of air conduction audiometers fitted with supra-aural earphones. The occluded-ear simulator (IEC 60318-4), the reference coupler (for the measurement of hearing aids) (IEC 60318-5) and the head and torso simulator (IEC 60959 TR) are used for the calibration of insert earphones and hearing aids. Finally, the mechanical coupler (IEC 60318-6) is used for the calibration of bone conduction audiometers. All have now been adopted as dual numbered BS EN standards, except the head and torso simulator (IEC 60959 TR).
IEC 60318-1 recently underwent revision, edition 2 being published in late 2009. The revised standard includes an extension of the frequency range to 16 kHz, expanded measurement uncertainties and integration of the scope of IEC 60318-2 for the measurement of circumaural headphones. Most significantly though, the new standard includes a method for determining the acoustical transfer impedance of ear simulators, along with associated tolerances.
The ISO 11904 series specifies basic framework measurement methods for sound immissions from sound sources placed close to the ear. This is applicable, for example, to exposure during equipment tests or at the workplace by earphones (or hearing protectors with audio communication facilities) and is applicable in the frequency range from 20 Hz to 16 000 Hz.
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| International Standards | National Standards |
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| IEC 60318-1:2009 Electroacoustics - Simulators of human head and ear - Part 1: Ear simulator for the measurement of supra-aural and circumaural earphones (new edition incorporates 60318-2, which is withdrawn) | BS EN 60318-1:2009 Electroacoustics. Simulators of human head and ear. Part 1: Ear simulator for the measurement of supra-aural and circumaural earphones |
| IEC 60318-3:1998 Electroacoustics - Simulators of human head and ear - Part 3: Acoustic coupler for the calibration of supra-aural earphones used in audiometry | BS EN 60318-3:1998 Electroacoustics. Simulators of human head and ear. Acoustic coupler for the calibration of supra-aural earphones used in audiometry |
| IEC 60318-4:2010 Electroacoustics - Simulators of human head and ear - Part 4: Occluded-ear simulator for the measurement of earphones coupled to the ear by means of ear inserts | BS 6310:1982 Specification for occluded-ear simulator for the measurement of earphones coupled to the ear by ear inserts (identical to IEC 60711:1981) |
| IEC 60318-5:2006 Electroacoustics - Simulators of human head and ear - Part 5: 2 cm3 coupler for the measurement of hearing aids and earphones coupled to the ear by means of ear inserts | BS EN 60318-5:2006 Electroacoustics. Simulators of human head and ear. 2 cm3 coupler for the measurement of hearing aids and earphones coupled to the ear by means of ear inserts |
| IEC 60318-6:2007 Electroacoustics - Simulators of human head and ear - Part 6: Mechanical coupler for the measurement on bone vibrators | BS EN 60318-6:2008 Electroacoustics. Simulators of human head and ear. Mechanical coupler for the measurement of bone vibrators |
| IEC 60959 TR:1990 Provisional head and torso simulator for acoustic measurements on air conduction hearing aids (will become IEC 60318-7, forecast 2011) | Not yet adopted as a BS |
| ISO 11904-1:2002 Acoustics - Determination of sound immission from sound sources placed close to the ear Part 1: Technique using a microphone in a real ear (MIRE technique) | BS EN ISO 11904-1:2002 Acoustics. Determination of sound immission from sound sources placed close to the ear. Technique using a microphone in a real ear (MIRE technique) |
| ISO 11904-2:2004 Acoustics -- Determination of sound immission from sound sources placed close to the ear -- Part 2: Technique using a manikin | BS EN ISO 11904-2:2004 Acoustics -- Determination of sound immission from sound sources placed close to the ear -- Part 2: Technique using a manikin |
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BSI/ISO/IEC websites
For the most up-to-date information regarding current audiometric standards, as well as pricing and ordering details on all the standards listed here, please contact the relevant standards organisation:
Members of the BSA (British Society of Audiology) can register for the BSA Standards Forum (hosted by NPL), which allows members to view and comment on standards which are currently in development or under revision.
NPL also offers audiometric calibration services, as well as training courses on all aspects of audiometry.