BS EN ISO 389-8:2004

This standard BS EN ISO 389-8:2004 Acoustics. Reference zero for the calibration of audiometric equipment is classified in these ICS categories:

• 11.040.01 Medical equipment in general
• 13.140 Noise with respect to human beings

This part of ISO 389 specifies reference equivalent threshold sound pressure levels (RETSPLs) for pure tones in the frequency range from 125 Hz to 8 kHz, applicable to the calibration of air conduction audiometers equipped with a particular model of circumaural earphones (SENNHEISER HDA 200).

NOTE 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 (see IEC 60645-2), the correction figures of the earphone for a free-field equivalent output are given in Annex C.