Intelligibility of Japanese sung vowels

抄録

The purpose of the present study is to investigate the intelligibility of Japanese sung vowels (/a/, /e/, /i/, /o/, and /u/) uttered in isolation by trained soprano singers at higher pitches varied between cg (nominal 554 Hz) and A5 (880 Hz). The utterance was made in following two different singing manners to see whether the intelligibility is improved by singing manners or not: one, so-called “classical singing” or Bel Canto, named “Sonorous” for short in this study, putting priority on sonority, and the other, named “Phonemic” for short, instructed to emphasize phonemic quality as Japanese vowels, holding the sonority as much as possible. Phonemic intelligibility test was carried out diotically through a headset in a rondomized order over six singers, five vowels, five pitches and two singing manners. It was found that the effect of the singing manner is significant for /a/, /e/, /i/ and /o/, “Phonemic” singing manner being superior to “Sonorous” one for /a/, /e/ and /i/, while for /o/ vice versa. For /u/, the effect was not found. It was also confirmed that the effect of the voice pitch is significant for /i/, /o/ and /u/, in which the intelligibility decreases with increasing pitch, in particular for /i/ and /u/, while for /a/ and /e/ the effect is not significant. For /a/, a higher intelligibility was obtained compared with other vowels despite of pitch increase. For all the vowels, in particular for /o/, the misperception rate as /a/ increased with increasing pitch.