Speech Signal Using Critical Filter Bank for Bilateral Sensorineural Hearing Impairment

Abstract: Sensorineural hearing impaired listeners face a particular problem in view of decrease in frequency resolving capacity of ear due to spread of spectral masking along the cochlear partition. Filtering speech signal by bank of critical band filters and adding signals from alternate bands for presenting to the two ears, is likely to reduce this effect, and thus may help in improving the speech intelligibility. We have implemented this processing scheme with eighteen critical bands for experimental evaluation. Listening tests were carried out using twelve vowel-consonant-vowel and consonant-vowel nonsense syllables presented in quiet, on ten subjects with mild-to-very severe sensorineural hearing loss. The stimulus response confusion matrices were analyzed for obtaining recognition scores and information transmission. The relative improvement in recognition scores is up to 25 percent. Information transmission analysis indicated that the overall improvement is contributed by improvements in transmission of place and manner features. The mean response time has also been found to significantly decrease