This part of ISO 8253 specifies relevant test signal characteristics, requirements for free, diffuse and quasi-free sound fieids, and procedures for sound field audiometry using pure tones, frequency modu-lated tones or other narrow-band test signals pre-sented by means of one or more loudspeakers, primarily for the purpose of determining hearing threshold levels in the frequency range from 125 Hz to 12 500 Hz.
It does not include specifications for the use of hand-held loudspeakers.
Speech as a test signal is not covered.
The purpose of this part of ISO 8253 is to ensure that tests of hearing, using sound field audiometry, give as high a degree of accuracy and reproducibility as possible.
Examples of graphical representations of the results and a bibliography are given in annexes A and C.