ANSI S3.6-1996 is the specification for Audiometers which represents current and best resources for information regarding audiometer calibration. It also contains reference threshold and noise levels for all commonly used transducers in one standard. ANSI S3.6-1996 incorporates existing ANSI, ISO, and IEC standards in an effort to obtain worldwide uniformity.
The same type of threshold audiometer is used to monitor the individual worker’s response to noise exposure. A baseline audio-gram is obtained before the worker is exposed to potentially Hearing measurement hazardous noise, periodically during the exposure times, and at the end of the worker’s exposures. Permissible exposure levels, the amount of time a worker may be exposed to noise without the necessity of engineering controls to reduce the noise, removing of the worker from the noise, or requiring that the worker use hearing protection, are founded on the maximum acceptable excess risk level of developing hearing impairment