Large-scale corpus of spontaneous speech can be an excellent resource for the study of language variations. This philosophy was reflected in the architecture of the Corpus of Spontaneous Japanese, or CSJ, that we have been compiling since 1999. In the first half of the paper, various characteristics of the CSJ were described in view of its application for the study of language variations. In the last half of the paper, the word-fusion of "de+wa" into "zya" was analyzed using the CSJ. It turned out that the main factor of the word fusion involved part-of-speech of "de" (either particle of auxiliary verb), type of speech (academic presentation or public speech), the degree of speaker's relaxedness, as measured by the frequency of laughter, and the interaction between the speech type and the frequency of laughter. The analyses of the interaction term suggested that low-frequency variations could be better perceptual cues of style shifting than high-frequency variations.
This article is a comparative sociolinguistic study of a sound change in Japanese: denasalization of velar nasal. Hibiya (1988) and Miyanaga and Matsuda (2001a, b) applied the methods of variationist sociolinguistics to spontaneous speech data collected in the cities of Tokyo and Takasago, Hyogo, respectively. Quantitative results derived from these two studies form the basis of comparison. We find that the variable process of velar nasal exhibits a remarkable similarity in both regional dialects.
Confusion between the Japanese stop /d/ and flap /r/ happens frequently to Taiwanese learners of Japanese, though it also happens to Japanese native speakers at times. In order to discover the difference in the recognition of these sounds between speakers of Japanese and Taiwanese, I used an identification task to measure categories of recognition, using 'closure duration', 'spike strength', and 'spike (transition) duration' as variables. Comparing both groups of speakers' recognition boundaries and the boundaries of identification at the 80%-level, many divergences were found. The result shows that Japanese native speakers achieved categorical recognition by using 'closure duration' as a major cue, but Taiwanese learners used in order of frequency, 'closure duration', 'spike duration', and 'spike strength' as cues to identify /d/ and /r/.