Ototoxic Drugs - drugs such as a special class of antibiotics, aminoglycoside antibiotics, that can damage the hearing and balance organs located in the inner ear for some individuals.

Outer Ear - external portion of the ear, consisting of the pinna, or auricle, and the ear canal.

Perilymph Fistula - leakage of inner ear fluid to the middle ear that occurs without apparent cause or that is associated with head trauma, physical exertion, or barotrauma.

Pervasive Developmental Disorders - disorders characterized by delays in several areas of development that may include socialization and communication.

Phonology - study of speech sounds.

Postlingually Deafened - individual who becomes deaf after having acquired language.

Prelingually Deafened - individual who is either born deaf or who lost his or her hearing early in childhood, before acquiring language.

Presbycusis - loss of hearing that gradually occurs because of changes in the inner or middle ear in individuals as they grow older.
Programmable Hearing Aids - This type of aid can be either digital or analog. It has different settings that allow the user to switch depending upon the hearing situation.

Reading Disorders - any of a group of problems characterized by difficulty using or understanding the symbol system for written language.

Receiver - the part of the hearing aid that sends the amplified sound into the ear.

Residual Hearing - For people with a partial hearing loss, this is the portion of their hearing that they retain.

Round Window - membrane separating the middle ear and inner ear.

Saturation Response - The loudest sound that a hearing aid is allowed to produce.

Sensorineural Hearing Loss - hearing loss caused by damage to the sensory cells and/or nerve fibers of the inner ear.

Semicircular Canals - The part of the ear that controls balance.

Sign Language - method of communication for people who are deaf or hard of hearing in which hand movements, gestures, and facial expressions convey grammatical structure and meaning.