Discrimination of Japanese fricatives and affricates by production boundaries in time and spectral domains: A case study of a female native speaker

Abstract

Acoustic features of fricatives (/s/ and /ɕ/) and affricates (/ʦ/ and /ʨ/) spoken by a female native speaker of Japanese were investigated. Discriminant analysis in the time domain revealed that fricatives (/s/ and /ɕ/) and affricates (/ʦ/ and /ʨ/) are well separated at a discriminant ratio of 98.0% (n = 508) when using the variables of the rise duration and the sum of steady and decay durations of the consonants' intensity envelope. Discriminant analysis in the spectral domain revealed that alveolar consonants (/s/ and /ʦ/) and alveolo-palatal consonants (/ɕ/ and /ʨ/) are well separated at a discriminant ratio of 99.2% (n = 508) when using the variable of the mean intensity of one-third-octave bandpass filter with a center frequency of 3,150 Hz. In addition, the four consonants were correctly identified at an accuracy rate of 97.2% (n = 508) when using a combination of production boundaries obtained in the above two discriminant analyses. Results suggest that the acoustic features of the four consonants can be represented by the time- and spectral-domain variables described above.