Voice-Quality Difference Between the Vowels in Filled Pauses and Ordinary Lexical Items

Acoustic differences between the vowels in filled pauses and ordinary lexical items such as nouns and verbs were examined to know if there was systematic difference of voice-quality. Statistical test of material taken from the Corpus of Spontaneous Japanese showed that, in most cases, there was significant difference of acoustic features like F0, F1, F2, intensity, jitter, shimmer, TL, H1-H2, H1-A2, duration, etc. between the two classes of vowels. Random forest classification of open data sets showed higher than 0.8 F-values on average. It turned out intensity, F0, F1, jitter, and H1-H2 were the most important acoustic features for the expected voice-quality difference.