Perceptual clustering of high-pitched vowels in Chinese Yue Opera

Abstract

Numerous studies on Western Opera singing have shown that listeners’ vowel identification performance decreases with an increasing fundamental frequency (fo). This study explores the intelligibility of high-pitched vowels in Yue Opera, the largest dialectal opera in China. Six long vowels (/i y e a o u/) were recorded by a professional female singer at ten fos between 220 and 932 Hz, of which 700-ms nuclei with flat fo contours and resonance trajectories were extracted as stimuli. In a within-subject design, sixteen phonetically trained listeners responded on a free-choice vowel quadrilateral (task 1) and in a two-alternative forced-choice task (task 2) to indicate which vowel was presented. Results show that vowels cluster in the perceptual space into three groups (/i y e/, /u o/, /a/) above 521 Hz and that listeners could identify vowels between but not within groups with high accuracy up to at least 932 Hz. Multidimensional scaling (MDS) of simulated auditory excitation patterns reveals highly differentiable spectral shapes between groups. These findings put into question whether previous results on Western Opera could be generalized to other forms of opera singing.