New directions for assessing speech perception in persons with sensory aids

This study examined the influence of stimulus variability and lexical difficulty on the speech perception performance of adults who used either multichannel cochlear implants or conventional heating aids. The effects of stimulus variability were examined by comparing word identification in single-talker versus multiple-talker conditions. Lexical effects were assessed by comparing recognition of 'easy' words (ie, words that occur frequently and have few phonemically similar words, or neighbors) with 'hard' words (ie, words with the opposite lexical characteristics). Word recognition performance was assessed in either closed- or open-set response formats. The results demonstrated that both stimulus variability and lexical difficulty influenced word recognition performance. Identification scores were poorer in the multiple-talker than in the single-talker conditions. Also, scores for lexically 'easy' items were better than those for 'hard' items. The effects of stimulus variability were not evident when a closed-set response format was employed.