Cognitive and Linguistic Contributions to Masked Speech Recognition in Children.

Purpose The goal of this study was to examine the effects of cognitive and linguistic skills on masked speech recognition for children with normal hearing in three different masking conditions: (a) speech-shaped noise (SSN), (b) amplitude-modulated SSN (AMSSN), and (c) two-talker speech (TTS). We hypothesized that children with better working memory and language skills would have better masked speech recognition than peers with poorer skills in these areas. Selective attention was predicted to affect performance in the TTS masker due to increased cognitive demands from informational masking. Method A group of 60 children in two age groups (5- to 6-year-olds and 9- to 10-year-olds) with normal hearing completed sentence recognition in SSN, AMSSN, and TTS masker conditions. Speech recognition thresholds for 50% correct were measured. Children also completed standardized measures of language, memory, and executive function. Results Children's speech recognition was poorer in the TTS relative to the SSN and AMSSN maskers. Older children had lower speech recognition thresholds than younger children for all masker conditions. Greater language abilities were associated with better sentence recognition for the younger children in all masker conditions, but there was no effect of language for older children. Better working memory and selective attention skills were associated with better masked sentence recognition for both age groups, but only in the TTS masker condition. Conclusions The decreasing influence of vocabulary on masked speech recognition for older children supports the idea that this relationship depends on an interaction between the language level of the stimuli and the listener's vocabulary. Increased cognitive demands associated with perceptually isolating the target talker and two competing masker talkers with a TTS masker may result in the recruitment of working memory and selective attention skills, effects that were not observed in SSN or AMSSN maskers. Future research should evaluate these effects across a broader range of stimuli or with children who have hearing loss.