Phonetic and intonation enhancement of speech for Japanese hearing-impaired speakers

We propose a system that is capable of improving intelligibility of speech by those with hearing impairment. We have found the speech often had problems in the intonation, the duration of the unvoiced consonants, and the tone of the voiced phonemes. The system systematically compensates problematic components of the speech using the counterparts in normal speech. It corrects the intonation using TD-PSOLA and elongates consonants by repeating the original waveform using inverting technique for making the result continuously connected until the duration reaches a threshold. Experimental results show that the proposed method successfully improves the intelligibility of the speech from 28% to 35% by making phonemes more articulated, and making double consonants, dasianpsila of syllabic consonant, and unvoiced consonants perceived clearer.