ISO 389-8:2004
Acoustics -- Reference zero for the calibration of audiometric equipment -- Part 8: Reference equivalent threshold sound pressure levels for pure tones and circumaural earphones
Product Details
Some notes and references on the derivation and the test conditions used to determine the recommended reference levels are given in Annex A and the Bibliography.
The sound attenuation of the earphone is given in Annex B. For speech audiometers of types A-E and B-E, the correction figures of the earphone for a free-field equivalent output are given in Annex C.