Wavelet packet analysis for reducing the effect of spectral masking to improve auditory perception

Abstract

Sensorineural hearing impaired person experiences degraded frequency selectivity of the ear, due to increase in spectral masking along the cochlear partition, results in degraded speech perception. Splitting the speech signal by means of filtering and down sampling at each decomposition level, using wavelet packets with different wavelet functions, helps to reduce the effect of spectral masking, through which it improve speech intelligibility. This experiment was carried out with vowel-consonant-vowel syllables for fifteen English consonants; they are decomposed in eight frequency bands with desired band selection. Dichotic presentation of the processed speech signal showed improvement in speech quality, recognition scores and less response time in the reception of speech feature of voicing, place, and manner, indicating usefulness of the scheme for better reception of spectral characteristics.