An articulatory and acoustic investigation of Mandarin apical vowels

Abstract

The present study investigates the articulatory and acoustic properties of apical vowels in Mandarin Chinese using ultrasound and acoustic measures. Instead of the high front vowel, dental and retroflex sibilants are known to be followed by apical vowels made with tongue tip/blade, rather than the tongue body. The ultrasound images of one Beijing speaker confirmed that the tongue tip/blade gesture indeed remains unreleased during the production of these vowels. However, it also revealed that the tongue body for apical vowels is significantly retracted with a relative order of the vowel following dentals being more retracted than the vowel following retroflexes. This gave rise to a consistent acoustic consequence; the second formant of the vowel after dentals of six Mandarin speakers was significantly lower than that of the vowel after retroflexes. In addition, the third formant of the vowel after a retroflex was significantly lowered and nearly merged with the second formant, indicating that the vowel is also strongly retroflexed. The correct analysis is thus claimed to include the apical gestures as secondary features added to the main articulation of the tongue body as in the following notation: a dentalized back vowel and a retroflexed mid vowel.