Perception and imitation of period-doubled phonation: Pitch and voice quality

Abstract

Period-doubled phonation, henceforth, period doubling, characterized by voicing periods that alternate in amplitudes and/or frequencies, is often perceived rough and with an indeterminate pitch. Lower pitch percept has been suggested by past studies when the degree of amplitude or frequency modulation increases. However, how listeners use period doubling when identifying linguistic tones remains unclear. The current study uses tasks of categorization with training, followed by imitation of tones manipulated with period doubling (with amplitude and frequency modulation, both separately and jointly) in a novel language. Native Mandarin and English speakers with different levels of music experience were tested. I show that period doubling leads to a low-tone bias in perception and imitation, especially as the modulation degree, particularly that of frequency, increases. Interestingly, interactions with stimulus f0 and modulation type show that in amplitude-modulated tokens, when compared to lower f0 (200 Hz), higher f0 (300 Hz) drives more low-tone responses. Period doubling is also imitated with lowered f0 and creaky quality. Language and music experience does not affect perceptual and imitative responses, suggesting that the perception of period doubling is not language-specific or conditioned by tonal knowledge. Period doubling likely signals low tones, even when the original f0 is high.