Hearing ability by telephone of patients with cochlear implants

We investigated the telephone communication ability of patients with cochlear implants who could understand conversations in natural voice without difficulty. The hearing ability of those patients with telephone adapters, which usually are used to reduce noise level in the telephone and to record into a tape recorder was also investigated. Vowel-confusion, consonant-confusion, and speech-tracking test results of patients listening to voices by telephone and by telephone adapter were compared with those of patients listening to natural, nontelephone voices. The average score of the speech-tracking test with natural voice was 111.5 phrases per 5 minutes. This score dropped to 62.4 by telephone. However, with a telephone adapter, the score of the speech-tracking test was 109.3 phrases par 5 minutes. This was almost the same score as that of the natural voice. So, generally speaking, the telephone communication ability of cochlear implant patients was not good enough. However, hearing ability with a telephone adapter came close to hearing ability during natural speech.