Comparative Analysis of Whispered and Normally Phonated Speech Using an LPC-10 Vocoder

摘要

The determination of the performance of an LPC-10 vocoder in the processing of adult male and female whispered and normally phonated connected speech was the focus of this study. The LPC-10 vocoder's analysis of whispered speech compared quite favorably with similar studies which used sound spectrographic processing techniques. Shifting from phonated speech to whispered speech caused a substantial increase in the phonomic formant frequencies and formant bandwidths for both male and female speakers. The data from this study showed no evidence that the LPC-10 vocoder's ability to process voices with pitch extremes and quality extremes was limited in any significant manner. A comparison of the unprocessed natural vowel waveforms and qualities with the synthesized vowel waveforms and qualities revealed almost imperceptible differences. An LPC-10 vocoder's ability to process linguistic and dialectical suprasegmental features such as intonation, rate and stress at low bit rates should be critical issue of concern for future research. Keywords: Speech processing; Linguistics; Phonetics.