Abstract
This paper aims to clarify the remaining traces of the Japanese labial /h/ sounds in Tohoku dialects, and to describe the characteristics of a gradual process in which the labials decline. Through an analysis of mouth shape, that visualizes lip movements in the articulation of the labials, the author attempts to describe various aspects and their transitional process. The results show some features that have not been recognized through aural analysis, which include leaving the mouth shape of labials, and using bilabial fricatives and labiodental fricatives. These findings suggest that traces of the Japanese labial /h/ sounds in Tohoku dialects are more broadly recognized than have been estimated, implying a geographically and generationally complex nature.
