Evidence for Tone-Specific Activity of the Sternohyoid Muscle in Modern Standard Chinese

Abstract

The role of the cricothyroid muscle (CT) in raising F0 is well understood, but the activity of F0-lowering strap muscles such as the sternohyoid (SH) has been less thoroughly investigated, especially in speech. This study focused on the activve participation of the SH in the production of tones 2 (mid-rising) and 4 (high-falling) in Modern Standard Chinese. The other tones, however, together with the role of the CT and vocalis muscles, were also investigated in order to replicate earlier findings and to provide a more comprehensive picture of the production of Chinese tones. EMG data recorded from two male speakers show that the SH is consistently utilized to reset F0 to a mid-low value at the onset of tone 2. Based on a comparison with earlier results for Thai speakers, we argue that this is a mandatory manoeuvre for producing rising F0 contours in most contexts. The SH muscle also participates in the F0 fall of tone 4, but less consistently. We argue that the latter manoeuvre may not be obligatory, especially in the case of speakers with a high-pitched voice.