Discrimination between fricative and affricate in Japanese using time and spectral domain variables

Previous studies on Japanese fricatives and affricates revealed that [s] and [ts] are classified by variables in the time domain (Yamakawa et al., 2012), whereas [ts] and [ʨ] as well as [s] and [ʨ] are classified by variables in the spectral domain (Yamakawa & Amano, 2011). To gain an integrated perspective on these findings, this study examined whether [s] [ts], and [ʨ] can be classified by a single discriminant model. Using variables in the time and spectral domains, canonical discriminant analysis was performed on word materials with [s], [ts], and [ʨ] pronounced by both single and multiple Japanese speakers. The time domain variables were a combination of the rise duration and sum of steady and decay durations of the three consonants. The spectral domain variable was their intensity obtained from a one-third-octave bandpass filter with a center frequency of 3150 Hz. The results showed that [s], [ts], and [ʨ] were successfully classified with high discriminant ratios of 92.6% and 90.2% for single and multi-speaker materials, respectively. This means that, in both cases, the single discriminant model can discriminate [s], [ts], and [ʨ] with the variables in the time and spectral domains.