Vijaya Kumar Narne1, C S Vanaja. 1. Department of Audiology, All India Institute of Speech and Hearing, Manasagangothri, Mysore, Karnataka, India. vijaynarne1@yahoo.co.in
Abstract
OBJECTIVE: To investigate the effect of background noise on perception of unprocessed and envelope-enhanced speech in individuals with auditory neuropathy (AN). DESIGN: Open-set speech identification abilities were assessed for unprocessed and envelope-enhanced speech in quiet and at three signal to noise ratios (10, 5, and 0 dB signal to noise ratio) in 15 individuals with AN. RESULTS: Results revealed that speech identification ability was affected more in the presence of noise than in quiet. The participants were classified into two groups, Good Performers and Poor Performers, based on their speech identification scores in quiet. It was observed that the reduction in mean speech identification scores in noise was less for Good Performers when compared with that of Poor Performers. Envelope enhancement of the signal improved speech identification scores in both the groups. The analysis of results also showed that Good Performers showed a significant improvement in all the conditions, whereas Poor Performers showed improvement only in quiet and +10 dB signal to noise ratio. CONCLUSIONS: For individuals with AN, listening in background noise is more difficult than in quiet condition. Envelope enhancement of speech signal improves speech identification scores in quiet and in background noise for individuals with AN. However, the benefit obtained varies depending on the speech identification ability in quiet.
OBJECTIVE: To investigate the effect of background noise on perception of unprocessed and envelope-enhanced speech in individuals with auditory neuropathy (AN). DESIGN: Open-set speech identification abilities were assessed for unprocessed and envelope-enhanced speech in quiet and at three signal to noise ratios (10, 5, and 0 dB signal to noise ratio) in 15 individuals with AN. RESULTS: Results revealed that speech identification ability was affected more in the presence of noise than in quiet. The participants were classified into two groups, Good Performers and Poor Performers, based on their speech identification scores in quiet. It was observed that the reduction in mean speech identification scores in noise was less for Good Performers when compared with that of Poor Performers. Envelope enhancement of the signal improved speech identification scores in both the groups. The analysis of results also showed that Good Performers showed a significant improvement in all the conditions, whereas Poor Performers showed improvement only in quiet and +10 dB signal to noise ratio. CONCLUSIONS: For individuals with AN, listening in background noise is more difficult than in quiet condition. Envelope enhancement of speech signal improves speech identification scores in quiet and in background noise for individuals with AN. However, the benefit obtained varies depending on the speech identification ability in quiet.