An analysis of the singleton-geminate contrast in Japanese fricatives and stops

Abstract

Previous acoustic analyses of the singleton-geminate contrast in Japanese have focused primarily on read speech. The present study instead analyzed the lengths of singleton and geminate productions of word-medial fricatives and voiceless stops in spontaneous monologues from the Corpus of Spontaneous Japanese (Maekawa, 2003). The results of a linear mixed effects regression model mirrored previous findings in read speech that the geminate effect (the durational difference between geminate and singletons) of stops is significantly larger than that of fricatives. This study also found a large range of variability in the geminate effect size between talkers. The size of the geminate effect between fricatives and voiceless stops was found to be slightly correlated, suggesting that they might be related to other rate-associated production differences between individuals. This suggestion was evaluated by exploring duration differences associated with talker age and gender. While there was no relationship between age and duration, males produced shorter durations than females for both fricatives and stops. However, the size of the geminate effect was not related to the gender of the speaker. The cause of these individual differences may be related to sound perception. Future research will investigate the cause of these individual differences in geminate effect size.