[The status of auditory function in auditory neuropathy].
To study the status of auditory function and the site of lesion in auditory neuropathy. The data of 65 patients were analyzed including the clinic signs, pure tone audiometry, auditory brainstem response(ABR), 40 Hz auditory event related potential(40 Hz AERP) and otoacoustic emissions (OAEs). The low frequency hearing loss in auditory neuropathy arose from the lesion of retrocochlear auditory afferent and efferent nerve and auditory brainstem, presented at the abnormality of acoustic reflex, efferent suppreSsion, ABR and the unparallel relationship between evoked OAE amplitude and pure tone threshold. To corresponding, the outer hair cells in low frequency region were out of suppression, presented at the strong response of SOAE, TEOAE and DPOAE in low frequency region. The high frequency hearing loss in auditory neuropathy arose from the lesion of cochlear outer hair cells, presented at the parallel relationship between DPOAE amplitude and pure tone threshold in high frequency region. The intermediate frequency hearing loss in auditory neuropathy was damaged gently or close to normal, presented at both pure tone threshold and DPOAE amplitude nearby 2 kHz were close to normal. The dysfunction in differ degree lied in the afferent and efferent nervous systems and cochlear level in auditory neuropathy, the main site of lesion was in the cochlear afferent and efferent nerve, up to the brainstem and down to the cochlea.