[Comparison of the residual hearing on the profound hearing-impaired children with the hearing aids and cochlear...

To compare the hearing test data of the profound hearing-impaired children with the hearing aids and with cochlear implants; to find out the useful method to measure the residual hearing.

Twenty-two profound hearing-impaired children participated in the study with complete set of hearing test and verbal rehabilitation file. Ten children fitted hearing aids and underwent verbal rehabilitation more than 3 months. Among the other 12 children with cochlear implants, 10 children fell in the same year range with the hearing aid patients. The children with hearing aids were divided into two groups according to the achievement of the verbal rehabilitation. ASSR threshold and pure- tone threshold were compared between the groups.

(1) ASSR test: 7 children (14 ears) with hearing aids achieved good verbal representation, in which ASSR threshold can be recorded on 2.71 frequency on average [(110.92 +/- 7.43) dB HL]. Among 3 children with hearing aids representing poor verbal achievement and 5 children with additional cochlear implant because of the poor verbal achievement with hearing aids, only 1.06 frequency had response of ASSR test [(110.88 +/- 48.52 ) dB HL]. (2) Pure tone audiometry: the average threshold of the 7 children with good representation was (96.11 +/- 7.81) dB HL, and the threshold on 3 frequency were less than 100 dB HL on average. The average threshold of the other 3 children with poor verbal achievement was (112.19 +/- 5.15) dB HL, and none of the frequency threshold was 100 dB HL.

The number of the frequency with the response of ASSR and the threshold < or =100 dB HL of pure tone audiometry is an effective indication of the useful residual hearing.