The Role of Breathy Voice in Hmu Tone Perception

Previous studies on tone perception have mainly focused on the role of F 0, while there are few but increasing studies on the effect of non-modal phonation. This study investigates the role of non-modal phonation in perceiving the five level tones used in Hmu, in which the lowest level tone (T11) is often referred to as “breathy voice”. First, an acoustic analysis was conducted on those tones to determine the voice quality and whether breathiness is limited to specific tones, revealing that breathiness only co-occurs with T11. Second, a perception experiment was performed to investigate whether breathiness can influence T11 identification. Results show that identification scores significantly differ only for the pairs of two continua that involve T11. This suggests that, relative to other tones, native speakers rely on breathiness in T11 identification, which derives from the accompanying phonation in its production. These findings shed light on how, alongside F 0, non-modal phonation contributes to tone perception, which demonstrates a new kind for the role of phonation in tonal contrasts. Considering these results, it is thus necessary to incorporate phonation cues when defining tone.