Testing Japanese loanword devoicing: Addressing task effects

In the loanword phonology of Japanese, voiced obstruent geminates ([bb, dd, gg]) have been claimed to devoice when they co-occur with another voiced obstruent within the same morpheme (e.g., /beddo/[betto] 'bed'). This devoicing pattern has contributed much to address a number of theoretical issues in the recent phonological literature. However, the relevant data have been primarily based on intuition-based data provided by Nishimura (2003) and Kawahara (2006). Kawahara (2011a, 2011b) addressed this issue by conducting rating studies using naive native speakers of Japanese. The results generally supported the intuition-based data by Nishimura (2003) and Kawahara (2006). However, the rating studies also revealed several aspects of the devoicing pattern that go beyond the intuition-based data as well. The current study further investigates the devoicing pattern by varying several task variables. In particular, this paper builds on Kawahara (2011a, 2011b) by adding (i) nonce word stimuli, (ii) a binary yes/no experiment, and (iii) auditory stimuli. The results show that (i) nonce words and real words behave similarly, but nonce words nevertheless show less variability across different grammatical conditions than real words; (ii) the binary yes/no experiment shows results similar to those of the scale-based experiment; and (iii) while auditory stimuli yield results comparable with those of orthographic stimuli, they also show an exaggerated effect of a phonetic implementation pattern. Overall, this paper uses Japanese as a case study, and finds some task effects in phonological judgment experiments. It is hoped that this paper stimulates further experimental research on phonological judgments of other phenomena in Japanese as well as in other languages.