711 is the 3-digit code to dial to reach a Telecommunications Relay Service (TRS) Operator for use when using a teletype (TTY) and phoning a person who is deaf or has limited hearing.
ABI
See Auditory Brainstem Implant.
ABR
See Auditory Brainstem Response testing.
AC
See Air Conduction.
Acoustic Neuroma
A slow-growing, benign tumor on the auditory and vestibular nerves that develops when cells that cover and insulate the nerves overproduce.
Acoustic Reflex
A contraction of muscles in the middle ear in response to loud sounds that that produces a stiffening of the eardrum. This helps reduce the damaging effects of loud sounds.