Acoustics -- Reference zero for the calibration of audiometric equipment -- Part 7: Reference threshold of hearing under free-field and diffuse-field listening conditions
This standard has been revised by ISO 389-7:2005.
Specifies a reference threshold of hearing for the calibration of audiometric equipment used under definite conditions. The listeners are otologically normal persons in the age from 18 to 25 years inclusive. The data are given in numerical form for the preferred frequencies in the one-third-octave series from 20 Hz to 16 000 Hz in accordance with ISO 266.