Speech perception and communication ability over the telephone by Mandarin-speaking children with cochlear implants

(1) To understand speech perception and communication ability through real telephone calls by Mandarin-speaking children with cochlear implants and compare them to live-voice perception, (2) to report the general condition of telephone use of this population, and (3) to investigate the factors that correlate with telephone speech perception performance.

Fifty-six children with over 4 years of implant use (aged 6.8-13.6 years, mean duration 8.0 years) took three speech perception tests administered using telephone and live voice to examine sentence, monosyllabic-word and Mandarin tone perception. The children also filled out a questionnaire survey investigating everyday telephone use. Wilcoxon signed-rank test was used to compare the scores between live-voice and telephone tests, and Pearson's test to examine the correlation between them.

The mean scores were 86.4%, 69.8% and 70.5% respectively for sentence, word and tone recognition over the telephone. The corresponding live-voice mean scores were 94.3%, 84.0% and 70.8%. Wilcoxon signed-rank test showed the sentence and word scores were significantly different between telephone and live voice test, while the tone recognition scores were not, indicating tone perception was less worsened by telephone transmission than words and sentences. Spearman's test showed that chronological age and duration of implant use were weakly correlated with the perception test scores. The questionnaire survey showed 78% of the children could initiate phone calls and 59% could use the telephone 2 years after implantation.

Implanted children are potentially capable of using the telephone 2 years after implantation, and communication ability over the telephone becomes satisfactory 4 years after implantation.