Hearing Loss

Decreased auditory perceptive ability. Such loss may be temporary (see adaptation, threshold shift), chronic or permanent (see acoustic trauma), and may occur in various ways:

• through occupational noise exposure (see boilermaker's disease, damage-risk criteria, impact sound, occupational deafness);
• through aging (see presbycusis);
• or through exposure to modern urban noise (see noise pollution, sociocusis).

These and related ailments (see acousma, diplacusis, hyperacusis, recruitment, tinnitus) are dealt with by a branch of medicine called otology, and are largely the result of problems in the middle ear and inner ear (see cochlea, organ of Corti).

Hearing loss, which is always acquired, should not be confused with deafness (anacusis) which refers to the complete inability to hear and is often congenital.

See also: Audiogram, Audiology, Audiometry, Conductive Hearing Loss, Hearing Level, Otology, Sensory-Neural Hearing Loss, Speech Interference Level.