The purpose of this study is to investigate how Korean learners control the length of Japanese fricatives and long and short vowels following the fricatives. This Experiment was conducted using a reading paradigm and the delay repetition technique with 36 meaningful words. 40 students learning Japanese pronounced these words using two different methods and were judged for the naturalness in terms of length.
The results revealed that there was a strong effect of two production methods on the voicing and length of fricatives. The factors that significantly affect the naturalness of the length of the fricatives were voicing of the fricatives, the length of the following vowel, the correctness of the single sound of fricatives, and two different methods.
Depending on different stimuli such as visual and auditory, learners were influenced by the voicing of the fricative. In the reading paradigm, the voiced fricative [z] preceding a short vowel /o/ and the voiced fricative [z] preceding a long vowel /oo/ were rated highly unnatural. On the other hand, the unvoiced fricative[s], [c] preceding a long vowel /oo/ at the end of the word increased the difficulty in producing the correct length in the delayed repetition technique.
In conclusion, this study offers the factors of timing control for the length of fricatives and also can contribute to the improvement of Japanese language education.