Deep band modulated phrase perception in quiet and noise in individuals with auditory neuropathy spectrum disorder and sensorineural hearing loss

Hemanth Narayan Shetty, Vishal Kooknoor

Noise and Health 2017 19(89):174-182

Context: Deep band modulation (DBM) improves speech perception in individuals with learning disability and older adults, who had temporal impairment in them. However, it is unclear on perception of DBM phrases at quiet and noise conditions in individuals with auditory neuropathy spectrum disorder (ANSD) and sensorineural hearing loss (SNHL), as these individuals suffer from temporal impairment. Aim: The aim is to study the effect of DBM and noise on phrase perception in individuals with normal hearing, SNHL, and ANSD. Settings and Design: A factorial design was used to study deep-band-modulated phrase perception in quiet and at noise. Materials and Methods: Twenty participants in each group (normal, SNHL, and ANSD) were included to assess phrase perception on four lists of each unprocessed (UP) and DBM phrases at different signal-to-noise ratios (SNRs) (−1, −3, and −5 dB SNR), which were presented at most comfortable level. In addition, a temporal processing was determined by gap detection threshold test. Statistical Analysis: A mixed analysis of variance was used to investigate main and interaction effects of conditions, noise, and groups. Further, a Pearson product moment correlation was used to document relationship between phrase perception and temporal processing among study participants in each experimental condition. Results: In each group, a significant improvement was observed in DBM phrase perception over UP phrase recognition in quiet and noise conditions. Although a significant improvement was observed, the benefit of recognition from DBM over UP is negligible at −5 dB SNR in both SNHL and ANSD groups. In addition, as expected, a significant improvement in phrase perception in each condition was found in normal hearing than SNHL followed by ANSD. Further, in both atypical groups, a strong negative correlation was found between phrase perception and gap detection threshold in each of the experimental condition. Conclusion: This is to conclude that temporal envelope cues from DBM were made available for phrase perception in those individuals who have temporal impairment.

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