scope:

This part of standard IEC 645 specifies general requirements for audiometers and particular requirements for pure-tone audiometers designed for use in determining hearing threshold levels in comparison with the standard reference threshold level by means of psycho-acoustic test methods. The purpose of this part is to ensure: a) that tests of hearing, particularly threshold, on a given human ear performed with different audiometers which comply with this part using methods described in ISO 8253-1 and ISO 6189 shall give substantially the same results; b) that the results obtained represent a valid comparison between the hearing of the ear tested and the reference threshold of hearing.