Contributions of auditory encoding and cognitive processing to degraded speech perception during adolescence

Previous studies demonstrated prolonged development of degraded speech perception, perhaps due to the maturation of auditory and cognitive brain regions. We investigated the contributions of auditory cortical encoding, measured by the acoustic change complex (ACC), and cognition to speech perception in adolescents (10–17) and young adults (18–23). Speech conditions included the QuickSIN and perception of 6-band noise-vocoded sentences, followed either by silence or multitalker babble. The ACC was measured to a frequency change condition (1000–950 Hz) and gap detection condition (10 ms gap in noise). Cognitive testing was also administered. Separate hierarchical stepwise regressions were completed for each condition. Preliminary results suggest that testing order (silence or babble first) exclusively affected performance on the NV silence condition. Encoding of timing information (ACC for gaps) contributed to the NV silence condition only, whereas encoding of spectral information (ACC for frequency) contributed to both NV speech conditions. Strategy use and sustained attention contributed to both NV speech conditions but age did not explain any unique variance after all factors were included. For the QuickSIN, auditory working memory and vocabulary contributed to performance, and age continued to influence performance after accounting for all other factors. [Funded by NIDCD.]