Notes: Maximum permissible 1/3 octave band level. If the Hearing Level to be measured is -10 dB
HL, then 10 dB should be subtracted from the levels listed in this table.
NOTE: A room providing sound isolation from ambient noise is highly
recommended so that hearing threshold values may be obtained. If a separate
examination (sound) room is used, it is considered sufficiently quiet for the
purposes of these tests if a group of otologically “normal” listeners with their
ears occluded is unable to detect any ambient noise during the test period. See
ANSI S3.1 (R2003) Criteria for Permissible Ambient Noise during Audiometric
Testing for maximum allowable outside octave band noise levels with three
prefabricated sound room types.
NOTE: Live voice testing requires a separate sound attenuated room for the
patient in order to avoid feedback and direct transmission of the test stimuli.