American Sign Language
Communication method used by the deaf in which gestures function as words.

Assistive Listening Device (ALD)
Using a microphone, transmitter component, receiver, and an earmold; it amplifies the sound source.

Atresia
Closure or absence of a body opening such the ear canal or outer ear.

Audiogram
Graph used to record the hearing responses of an individual when different frequencies and intensities are applied.

Audiometer
Electronic instrument used to measure hearing sensitivity.

Audiology
The study of hearing - identification, evaluation, habilitation, and rehabilitation of hearing loss.

Audiometry
Testing that involves hearing.

Auditory Brainstem Response (ABR)
A type of audiometry that measures electrical activity from the auditory nerve and brainstem.

Auditory Canal
Structure that leads from the outer ear (auricle/ pinna) to the eardrum (tympanic membrane).

Auditory Cortex
Area or brain where neural impulses are processed into meaningful bits of auditory information.

Auditory Nerve
Cranial nerve that carries auditory impulses/ messages from the inner ear to the brainstem and brain.

Aural rehabilitation
Procedures used with hearing impaired persons to improve the communication ability.