Speaking rate effects on Japanese vowel and consonant length contrasts

Abstract

This study examines the sensitivity of vowels and consonants to speaking rate variations in both production and perception, using Japanese as a case study. In contrast to prior studies, which suggest that vowels are more responsive to speaking rate changes than consonants in production, our results indicate a more nuanced distinction between vowels and stops versus fricatives and nasals, with the former group exhibiting greater sensitivity to speaking rate changes. Furthermore, this production pattern was also generally reflected, though to a lesser extent, in the perception results. These findings point to the need for further research into factors such as the presence or absence of length distinctions, language-specific prosodic and rhythmic characteristics, and the relationship between the ratios of long to short segments and slow to fast speaking rates.