Discrimination of intonation contours by adolescents with cochlear implants

Differences in fundamental frequency (F0) contour peak alignment contribute to the perception of pitch accents in speech intonation. The present study assessed the discrimination of differences in F0 contour peak alignment by adolescent users of cochlear implants (CIs).

In Experiment 1, subjects discriminated between rise-fall F0 contours located early in the syllable and those aligned late. Recorded utterances with manipulated F0 were used as stimuli and all subjects wore a unilateral CI. In Experiment 2, bilaterally-implanted subjects repeated Experiment 1 in the bilateral condition.

Twenty-one CI users aged 12-21 years participated. A normally-hearing control group (n = 20) also completed Experiment 1.

Listeners with normal hearing (NH) could discriminate between F0 peaks differing by 80 ms or more. Results varied among the CI users, with only four users displaying a pattern of results similar to that of the NH listeners. Sixteen CI users responded inconsistently or at chance levels (p > 0.05; binomial test). Ten CI users who were bilaterally implanted completed the tests in unilateral and bilateral listening conditions.

Results suggest that CI users may have difficulty discriminating between F0 alignment and that use of bilateral implants did not provide an advantage to discrimination.