Articulation Scores of Spectrum-peak Enhanced Consonants

Abstract

In this study, a time-variant adaptive digital filter was designed for the purpose of improving the articulation scores of Japanese consonant-vowell syllables in the hearing impaired. In the system, some band-pass filters were generated beforehand which match the human auditory filters. The local peaks of consonant spectrum in high frequency were selectively detected by the running spectrum method, and the proper filter characteristics were adopted to the monosyllables to enhance transient formants and band noise of consonants. Articulation scores and phonetic confusion among the original and modified syllables were experimentally investigated with the pseudo hearing impaired. As a result, modified plosives improved the articulation, however, modified fricatives increased phonetic confusion. Other monosyllables decreased confusion, but exhibited no significant improvement. These results suggest that enhancing the local peaks of consonant is effective to the consonants where formant transients are used as a psychoacoustic cue in auditory perception.