Hidden hearing loss (HHL) is a popular topic referring to complaints of hearing difficulty or perceived hearing loss despite having “normal” audiometric thresholds. Within the scientific literature, this term has most recently been used to refer specifically to the reduced amplitude of sound-evoked neural responses that occurs with loss of synapses that connect the inner hair cells (IHCs) to the auditory nerve. In other words, the patient’s audiometric difficulties are hidden behind a normal audiogram.
Topic(s): Normal Hearing, perceived hearing complaint, Hidden Hearing Loss (HHL), audiometric threshold, Audiometric Test, inner hair cell (IHC), pure-tone average (PTA), extended high frequencies (EHF), Central auditory processing disorder (CAPD), Auditory Neuropathy Spectrum Disorder ANSD, Tinnitus, hearing handicap inventory for the elderly (HHIE), hearing handicap inventory for the adults (HHIA), noise-induced synaptopathy, auditory brainstem response (ABR), temporary threshold shift (TTS), synaptopathy, speech-in-noise testing (QuickSIN), word-in-noise test, otoacoustic emissions (OAEs), tympanometry and middle-ear muscle reflexes (MEMR), dichotic processing, temporal processing, monaural low-redundancy, binaural interaction, spatial processing, Distortion product otoacoustic emissions (DPOAE), Transient Evoked Otoacoustic Emissions (TEOAE), Auditory Evoked Response
Otoacoustic emissions (OAEs), low-level sounds produced by the healthy cochlea, require normal or near-normal outer hair cells (OHCs) to provide amplification of the backward traveling waves so the outgoing energy can be detected in the ear canal and, for some types of OAEs, to produce the nonlinearities that give rise to the emission itself. As most audiologists know, these low-level acoustic by-products provide an invaluable window into the otherwise inaccessible cochlea and a useful gauge of OHC health and hearing.
Topic(s): otoacoustic emissions (OAEs), Hearing