Discrimination between fricatives and affricates pronounced by Japanese native speakers at various speaking rates
Kimiko Yamakawa, Shigeaki Amano · The Journal of the Acoustical Society of America · 2013
Fricatives [s] and affricates [ts] uttered at a normal speaking rate are successfully discriminated with two variables: a rise part duration and a steady + decay part duration [Yamakawa et al., Acoust. Sci. Tech. 33(3), 154–159 (2012)]. This study examined whether [s] and [ts] uttered at various speaking rates are also well discriminated with these variables. Discriminant analyses with the two variables were performed on [s] and [ts] in word-initial position in a carrier sentence pronounced by eight native Japanese speakers at fast, normal, and slow speaking rates. Discriminant error rates were low for the fast (9.8%, n = 512), normal (5.7%, n = 512), and slow (13.1%, n =512) speaking rates. However, the error rate was high (22.0%, n = 1536) when the three speaking rates were analyzed together. It decreased to 15.7% when the two variables were normalized with an averaged mora duration of the carrier sentence. These results suggest that [s] and [ts] can be discriminated at various speaking rates with a normalized rise part duration and normalized steady + decay part duration. [This work was supported by JSPS KAKENHI Grant Numbers 22720173, 24652087, and 25284080, and by Aichi Shukutoku University Special Research Grant 2011-2012 and Corporate Research Grant 2013-2014.]