Individual differences in talker discrimination among adult cochlear implant users

Real-world speech communication involves interacting with talkers with diverse voices and accents. Adult cochlear implant (CI) users often demonstrate poor discrimination of talkers’ voices relative to their normal-hearing peers, which may contribute to difficulties in understanding speech produced by multiple talkers. However, the factors underlying poor talker discrimination ability are not well understood. The current study examined auditory and cognitive-linguistic factors that support talker discrimination, and explored the association between talker discrimination and sentence recognition across CI users. In an AX talker discrimination task, 25 adult CI users indicated whether word pairs were produced by the same talker or by two different talkers. Participants also completed measures of spectrotemporal processing, cognitive-linguistic skills, including fluid intelligence, working memory capacity, inhibitory control, and phonological processing, and sentence recognition. Results showed that talker discrimination scores (accuracy, sensitivity) were moderately to strongly correlated with spectrotemporal processing, fluid intelligence, inhibitory control, and phonological processing. Talker discrimination scores were also related to sentence recognition accuracy scores across CI users. These preliminary findings suggest that both auditory and cognitive-linguistic processes support talker discrimination, and, furthermore, may underlie the relationship between talker discrimination and sentence recognition in adult CI users.