Application of bone-conductive and free field auditory steady-state response for multiply-handicapped children with hearing loss

Abstract

Estimating the hearing threshold in multiply-handicapped children is so difficlt that diagnosis of hearing loss and rehabilitation are usually delayed. Recently, the auditory steady-state resopnse (ASSR) test has been used as a measure of hearing sensitivity. In the present study, we investigated the effectiveness of ASSR for estimating the hearing threshold in multiply-handicapped children.
Fifteen multiply-handicapped children were studied, ranging in age from 1 to 12 years with suspected severe hearing loss detected with ABR or infant audiometry. Both ears of all the subjects were tested with MASTER (Bio Logic Corporation). Airconducted ASSRs were recorded with carrier frequencies of 0.5, 1, 2, and 4kHz under sedation. Furthermore, in some cases, bone-conducted ASSR and free field ASSR with hearing aids were recorded.
In all cases, ASSR thresholds were recorded. Under the condition of bone-conducted recordings, ASSR would possibly distinguish between conductive and sensorineural hearing loss. Under the in condition of free field recordings, ASSR could possibly evaluate functional gains.
This suggested that ASSR might be helpful for planning therapy, and in selecting candidate suitable for hearing aids and cochlear implantation among multiply-handicapped children.