Effect of CVR modification on automatic recognition of stop consonants in isolated VCV utterances by an HMM based ASR system

Consonant-Vowel-Ratio (CVR) modification is a technique involving selective amplification of consonant segments with respect to the nearby vowel segments. CVR modification is reported to be effective for improving recognition of consonants by normal hearing listeners in adverse listening conditions and also for listeners with hearing impairments. In this paper, we have investigated the effect of CVR modification on recognition of stop consonants in vowel-consonant-vowel (VCV) utterances by an automatic speech recogniser (ASR) based on hidden Markov model (HMM). The results indicate CVR modification to be effective in improving recognition of stop consonants by nearly 6 to 7 % in the presence of additive noise.