Performance of Children with Cochlear Implants, Tactile Aids, and Hearing Aids

Abstract

This investigation compared the speech perception skills of children with prelingual profound deafness who used the multichannel Tactaid 7 (TA7) (n = 9) to those of a matched group of children who used the Nucleus 22-channel cochlear implant (CI) (n = 10) at a predevice interval, and after an average of 1.8 years of multichannel device use. Performance was assessed with closed-set measures of phoneme and word recognition, and on an open-set test of phrase recognition. Several measures evaluated perception with cues from the device alone; one measure assessed device-plus-lipreading performance. The results demonstrated that the CI group's performance improved significantly between the pre- and postdevice intervals on all measures. The scores of the TA7 users showed little change with increased device use, except on the measure of closed-set word recognition and the measure of sentence perception with lipreading, on which small improvements were observed. As a result, the scores of the CI group were significantly higher than those of the TA7 group on all measures at the postdevice interval. The speech perception abilities of the CI and the TA7 groups at the postdevice interval were next compared to that of matched children with prelingual deafness who used conventional hearing aids (HA). Hearing aid subjects were grouped by unaided thresholds: Gold subjects (PTA = 94 dB HL) and Silver subjects (PTA = 103 dB HL). The performance of the Tactaid 7 group was significantly poorer than that of the Gold HA subjects on all measures, and poorer than that of the Silver HA subjects on open-set sentence recognition in the auditory-only modality. In contrast, there were no significant differences between the performance of the CI group and the two HA groups. The current results suggest that children with CIs learned to recognize words and understand speech without lipreading, and that their speech perception abilities approach that of children with profound hearing impairment who obtain some benefit from conventional amplification. However, children with the TA7 demonstrated only limited speech understanding, even when auditory cues were combined with speechreading.