ANSI/ASA S3.1-1999 (R2008)

This standard specifies maximum permissible ambient noise levels (MPANLs) allowed in an audiometric test room that would produce negligible masking (less than or equal to 2 dB) of test signals presented at reference equivalent threshold levels specified in ANSI S3.6. The MPANLs are specified for octave and one-third octave band intervals from 125 to 8000 Hz for two audiometric testing conditions (ears covered and ears not covered) and for three test frequency ranges (125 to 8000 Hz, 250 to 8000 Hz, and 500 to 8000 Hz). This standard is intended for use by all persons testing hearing and for distributors, installers, designers, and manufacturers of audiometric test rooms.

This document reaffirmed on 15 October 2003.