Differential relations of auditory and cognitive functions to speech recognition tasks in adult cochlear implant users

Abstract

Clinical testing for assessing adult cochlear implant (CI) candidacy and outcomes relies primarily on tasks of open-set recognition for words and sentences. However, it is not clear in what ways performance on these different tasks relates differentially to auditory and cognitive functions. We tested the hypothesis that auditory and cognitive functions would contribute differentially to performance on recognition of isolated words (CID-W22 words), meaningful sentences (Harvard Standard), nonsense sentences (Harvard Anomalous), and sentences with high talker variability (PRESTO) in adult CI users. Sixty-five experienced CI users completed a battery of auditory and cognitive tests to assess auditory spectro-temporal processing, vocabulary size, working memory capacity, inhibition-concentration, nonverbal reasoning, and speed of lexical access. Findings were that spectro-temporal processing, lexical access speed, and nonverbal reasoning predicted scores across all word and sentence recognition tests. In contrast, inhibition-concentration contributed to nonsense sentence recognition, while vocabulary knowledge contributed to high talker variability sentence recognition. Results suggest that there is a core set of auditory and cognitive functions that contribute broadly to speech recognition, while more specific cognitive functions contribute to performance on some speech recognition tasks. Clinical implications are that individual cognitive abilities should be considered when evaluating CI candidacy and outcomes.