Durational compensation within a CV mora in spontaneous Japanese: Evidence from the Corpus of Spontaneous Japanese

Previous experimental studies showed that in Japanese, vowels are longer after shorter onset consonants; there is durational compensation within a CV-mora. In order to address whether this compensation occurs in natural speech, this study re-examines this observation using the Corpus of Spontaneous Japanese. The results, which are based on more than 200 000 CV-mora tokens, show that there is a negative correlation between the onset consonant and the following vowel in terms of their duration. The statistical significance of this negative correlation is assessed by a traditional correlation analysis as well as a bootstrap resampling analysis, which both show that it is unlikely that the observed compensation effect occurred by chance. The compensation is not perfect, however, suggesting that it is a stochastic tendency rather than an absolute principle. This paper closes with a discussion of potential factors that may interact with the durational compensation effect.