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Table 1. Definitions of Common Terminology
Sudden Hearing
Loss (SHL)
A rapid-onset subjective sensation of hearing impairment in
one or both ears.
Sensorineural
Hearing Loss
(SNHL)
Hearing loss resulting from abnormal function of the
cochlea, auditory nerve, or higher aspects of central auditory
perception or processing.
Conductive Hearing
Loss (CHL)
Hearing loss resulting from a problem conducting sound
waves anywhere along the route through the outer ear,
tympanic membrane, or middle ear.
Mixed Hearing Loss
(MHL)
Hearing loss resulting from both SNHL and CHL occurring
in the same ear.
Sudden
Sensorineural
Hearing Loss
(SSNHL)
A subset of SHL that is a) sensorineural in nature, b) occurs
within a 72-hour window, and c) consists of a decrease in
hearing of greater than or equal to 30 decibels affecting at
least 3 consecutive frequencies.
Idiopathic Sudden
Sensorineural
Hearing Loss
(ISSNHL)
SSNHL with no identifiable cause despite adequate
investigation.
Salvage erapy Any therapy offered aer 2 weeks from symptom onset (even
if initial therapy was observation).
