For a specified signal, amount in decibels by which the hearing threshold for a listener, for one or both ears, exceeds a specified reference equivalent threshold level. Unit, dB (ANSI S1.1-1994: hearing level; hearing threshold level).

See Hearing Level.

Minimal hearing level at which an individual responds to a pure tone test at least 50 percent of the time.

The lowest threshold that the employee can hear the test tone during an audiometric test. The HTL's are recorded on the employee's audiogram.

Amount in decibels that a specified signal can exceed to cause damage to the ears of a listener.