Dichotic presentation of speech signal with critical band filtering for improving speech perception

Reduction in tlequency resolving capacity of the auditory system due to spread of masking of frequency cornponents by neighboring frequency components degrades speech perception in cases of sensorineural hearing impairment. We have carried out experimental evaluation of splitting speech into two signals lby using a bank of critical band filters, in order to reduce the effect of spectral masking in the cochlea. The dichotically presented signals are perceptually integrated in the auditory cortex. Listening tests were carried out with vowel-consonantvowel and consonant-vowel syllables for twelve English consonants on five normal hearing subjects with simulai ion of sensorineural impairment done by adding white masking noise to the speech signal at various S”. Significant improvements in recognition score were obtained under adverse listening conditian. Improvement in the reception of speech feature of voicing, place, and manner was observed in information transmission analysis.