What is period doubling?

My dissertation investigates how sub-phonemic differences in voice contribute to tone contrasts in Mandarin Chinese by focusing on period-doubled voice and its role in pitch and tone perception.

Period doubling is one of the most common types of creaky voice, (~25% in normal speakers’ utterances; Klatt & Klatt, 1990), for example, the creaky voice in Mandarin Tone 3 is often realized as period doubling. Despite so, it is better known from studies of pathological voice and singing styles as “diplophonic voice” (Gerratt et al., 1988; Bailly et al., 2010 among others): diplophonia, dysphonia, throat singing in Mongolian folk music, Tibetan chants, Sardinian, and Japanese traditional singing.

It consists of two simultaneous harmonics of different frequencies, and often results in bitonal and rough voice sounding (Redi & Shattuck-Hufnagel, 2001; Keating et al., 2015). Given the presence of multiple f0s, the pitch during period doubling is often indeterminate, and so it is unclear whether tone is identifiable in period doubling.

The dissertation project serves as a probe of how people produce and make use of voice quality when processing linguistic information. The goals are threefold: 1) to determine the articulatory and acoustic features and linguistic distributions of period doubling, compared to those of another common creaky voice, vocal fry; 2) to investigate the interaction between perceived pitch and voice quality in period doubling; 3) to probe the role of period doubling in lexical tone perception.

Sample tokens of voice types in corpus