Coordinated systems in Taiwan Mandarin tone production: An investigation of laryngeal and tongue movements

Abstract

While electroglottography (EGG) is commonly used to examine different phonation types as well as laryngeal closure and opening of segments, only limited EGG studies focus on tonal quality [Brunelle et al., 2010, Phonetica, 67:147]. In particular, it is not yet clear how laryngeal movements in terms of its vibration magnitude and vertical displacement may be associated with pitch contour in tone production. The current study tackles this question by examining the amplitude of EGG pulses and laryngeal heights across four tones in Taiwan Mandarin. Ultrasound images are also obtained to assess the temporal relationship between tongue positioning and laryngeal movements during tone production. Preliminary results show that while the laryngeal area is more constricted by low, back vowels, a stronger correlation between EGG amplitude and pitch contour is found. On the other hand, when the tongue is positioned in the front of the cavity, larger degrees of freedom around the laryngeal area yield a lesser correlation between EGG amplitude and pitch contour but a stronger correlation between laryngeal height and pitch contour. The results suggest that tone production may be a result of a combination of laryngeal vibration and spatial coordination between the laryngeal and supralaryngeal movements. [Funding from MOST.]