Faculty Bibliography

On the basis of the good predictions for phonemes correct, we conclude that closed-set feature identification may successfully predict phoneme identification in an open-set word recognition task. For word recognition, however, the PCM model underpredicted observed performance, and the addition of a mental lexicon (ie, the SPAMR model) was needed for a good match to data averaged across 7 adults with CIs. The predictions for words correct improved with the addition of a lexicon, providing support for the hypothesis that lexical information is used in open-set spoken word recognition by CI users. The perception of words more complex than CNCs is also likely to require lexical knowledge (Frisch et al, this supplement, pp 60-62) In the future, we will use the performance off individual CI users on psychophysical tasks to generate predicted vowel and consonant confusion matrices to be used to predict open-set spoken word recognition. $$:

This study considers the validity of the Words and Gestures and Words and Sentences portions of the MacArthur Communicative Development Inventories (MCDI) for pediatric cochlear implant users who exceed the age ranges for which these inventories were normed. In Experiment 1, scores on the Words and Gestures measures were compared with scores on behavioral receptive and expressive vocabulary and language measures at preimplantation and again at 6 months postimplantation. Children ranged in age from 17 to 72 months, and results revealed significant correlations (r-values:.38-.80), with the strongest correlations resulting between MCDI measures and raw scores derived using the Reynell Developmental Language Scales (RDLS). Correlations also obtained between the number of words produced reported on the MCDI Words and Gestures inventory and the Peabody Picture Vocabulary Test-Third Edition (PPVT-III). Experiment 2 compared scores on the Words and Sentences measures with the same behavioral receptive and expressive vocabulary and language measures at 12 and 18 months postimplantation. Children ranged in age from 38 months to 67 months, and significant correlations obtained between behavioral measures and Words and Sentences measures assessing word production as well as grammatical ability (r-values:.60-.90). The strong validity findings motivated Experiment 3, in which predictive formulas were developed to predict scores on the RDLS based on scores from the MCDI. These models will allow researchers and clinicians to use a single index to assess the language abilities of a broad range of ages and performance abilities within the pediatric cochlear implant population. $$:

This study examined the speech intelligibility of profoundly, prelingually or congenitally deaf children who use hearing aids. Children were 1-15 years old and they were classified into subgroups according to residual hearing (pure-tone averages [PTAs] between 90 and 100 dB HL, 100 and 110 dB HL, or greater than 110 dB HL) and communication mode (either oral or Total Communication [TC]). They read lists of standard sentences which were played back to panels of three naive listeners who were not familiar with the speech of the deaf and who did not know to which subgroup the children belonged. The data revealed a strong significant trend toward higher intelligibility for children with more residual hearing, and a significant trend toward higher intelligibility for users of oral communication than for those who used Total Communication. However, the latter trend was much more pronounced for some ranges of residual hearing than for others, and it may have been partly due to a sampling effect. A third trend showed significantly higher intelligibility levels at older ages, but this was particularly pronounced for children with PTAs between 90 and 100 dB HL, and for the majority of oral communication users (and only a few Total Communication users) with PTAs between 100 and 110 dB HL. These results suggest that the amount of residual hearing (possibly in interaction with the communication mode used by the child) may be an important factor in the development of intelligible speech. $$: