Subtle Differences between the Speech of Young Speakers of 'Accentless' and Standard Japanese Dialects: An Analysis of Pitch Peak Alignment

Japanese dialects are largely classified into two types in terms of prosodic systems, one having a lexical pitch contrast and the other having no such contrast. Dialects of the latter type are called ‘accentless’ dialects. Many previous studies reported that, in areas where an accentless dialect had been originally spoken, younger speakers acquired Standard Japanese lexical pitch accent and are thus no longer accentless. We replicated this finding when we followed the traditional approach of categorically labeling recorded tokens. However, an acoustic analysis revealed that there was a phonetic difference between the speakers from the accentless region (Accentless Group) and those from the Standard Japanese region (Standard Group); the alignment of the F0 peak in accented words tended to be delayed more in the Accentless Group than the Standard Group. This difference is probably due to the substratum interference of the original accentless dialect.