Lexical influences on speech perception by children with multichannel cochlear implants

Abstract

This study examined lexical effects on word recognition by children with multichannel cochlear implants. Based on computational analyses, word lists were constructed to allow systematic examination of the effects of word frequency, lexical density (i.e., the number of phonemically similar words, or neighbors), mean neighborhood word frequency, and word length. The percent of words correctly identified was significantly higher for lexically ‘‘easy’’ words (high frequency words with few neighbors) than for ‘‘hard’’ words (low frequency words with many neighbors). The percent of phonemes correctly identified did not differ between the ‘‘easy’’ and ‘‘hard’’ words, suggesting that phoneme scores do not accurately reflect word recognition. Word recognition scores were also better for multisyllabic than for monosyllabic words. These results demonstrate that children with multichannel cochlear implants systematically organize words in long-term lexical memory using processes similar to listeners with normal hearing. Lexical effects will also be examined on a longitudinal basis to determine if performance increases with implant use. [Work supported by NIH.]