Original Research Article
Year: 2020 | Month: December | Volume: 10 | Issue: 12 | Pages: 302-313
Effect of Consonant-Vowel Ratio Enhancement and Duration Enhancement on Speech Perception among Individuals with Auditory Neuropathy Spectrum Disorders
Priyanka Jaisinghania, P. Manjulab
a DST INSPIRE Fellow, All India Institute of Speech and Hearing, Mysuru, (Karnataka), India
b Professor of Audiology, Department of Audiology, All India Institute of Speech and Hearing, Mysuru, (Karnataka), India
Corresponding Author: Priyanka Jaisinghani
ABSTRACT
Purpose: Management of individuals with Auditory Neuropathy Spectrum Disorders has always been an enigma. The present study evaluated the effect of speech enhancement strategies i.e., Consonant-Vowel Ratio Enhancement (CVRE) and Duration enhancement (DE), on speech identification in quiet, in individuals with ANSD.
Methods: Repeated measures design was used for the study on thirteen individuals with ANSD. Speech identification scores were obtained for sentences in Original, with CVRE by 9 dB & 12 dB, and DE conditions. The stimuli were presented to the test ear of participants through audiometric headphones at 40 dB SL (ref: SRT). Verbal responses were audio recorded and the raw speech identification scores across four conditions were tabulated.
Results: Out of 13 participants, DE improved the raw SIS in four individuals, CVRE-9 in three and CVRE-12 in seven individuals. The mean and median of raw SIS was higher with DE in comparison to CVRE and original conditions. No significant difference was noted in the raw scores with and without speech enhancement strategies in individuals with ANSD. This could be because first, CVRE efficiently enhanced the alveolar stops and affricates however, only a portion of the Kannada sentence was enhanced by CVRE and it remained largely unaltered. Second, syllable vowel context is found to influence the medial consonant identification in DE. Since, a sentence structure has diverse CV combinations which could have possibly contributed to no difference in speech identification with DE. Third, longer vowel durations with DE may also have led to excessive backward masking of the preceding consonant.
Conclusion: Both CVRE and DE did not enhance the speech identification.
Key words: duration enhancement, consonant-vowel ratio enhancement, speech identification.