Peter Flipsen Jr., Ph.D. & Lana G. Colvard, M.A. The University of Tennessee, Knoxville Intelligibility of Speech Produced by Young Children with Cochlear Implants Bionic Ear Institute - May 21, 2002

Intro 1 st year report on longitudinal study Six children to be tested multiple times. Tested individually every 3 months in a sound treated booth. Analysis based on conversational speech and using the Children’s Speech Intelligibility Measure (CSIM). Bionic Ear Institute - May 21, 2002

Method Participants were all profoundly hearing-impaired and received their implants by age 3 years. See Table 1. Participants had months of implant experience at initial testing (mean = 31.7 months). CSIM judged by groups of 3 listeners using a multiple-choice (pick 1/12) task. Conversation transcribed using orthographic transcription with intelligibility calculated using procedures as in Shriberg (1986). Unintelligible portions marked as * per syllable. Converted to words assuming 1.15 syllables per word. Bionic Ear Institute - May 21, 2002

Results Findings for the CSIM are shown in Figure 1. Test-retest reliability using 10% of the samples indicated a standard error of measurement (SEM) of 4.3%. Comparing Time 1 to Time 5 (and accounting for SEM) single-word intelligibility increased for participants 2, 5 & 6 but stayed about the same for the other three participants. Single-word intelligibility was not significantly correlated with the amount of implant use (p >.05). Bionic Ear Institute - May 21, 2002

Results (cont’d) Findings for conversational speech intelligibility are shown in Figure 2. From Time 1 to Time 5, intelligibility in conversation increased for participants 4, 5, & 6 but stayed about the same for the other three participants. Intelligibility in conversation was not significantly correlated with the amount of implant use (p >.05). Bionic Ear Institute - May 21, 2002

Overall Conversational intelligibility always exceeded single-word intelligibility. Single-word and conversational intelligibility were significantly correlated with each other (r =.70, p <.001). Bionic Ear Institute - May 21, 2002

Overall Participant 2 may have been an outlier. Identified earliest (only one at birth) Highest score on PPVT Better performance on several other language measures. The correlations between intelligibility scores and implant use were then repeated excluding participant 2. A significant correlation (r =.52, p <.01) was obtained for conversational speech only. Bionic Ear Institute - May 21, 2002

Discussion Single-word intelligibility was not correlated with implant use. The imitation format of the CSIM may have affected the findings. Intelligibility in conversation was already quite high at Time 1. Thus intelligibility gains appear to be rapid within the first two years after implantation. The exact relationship between intelligibility performance in single-words and in conversation needs further investigation. Bionic Ear Institute - May 21, 2002

Acknowledgments Many thanks to Julie Beeler, Velvet Buehler, Molly Erickson, Mark Hedrick, Marge Hudson, Gayla Hutsell, Kim Jenkins, Leslie Jolles, Amy Kibler, and Saneta Thurman for their assistance with this study. Special thanks to Michelle LaGesse for participant testing and to Lisa Moss for transcribing the conversational speech samples. Many thanks also to the children who participated and their parents. Bionic Ear Institute - May 21, 2002