This research focuses on the study of upper and lower lip movements in the production of the Italian bilabial stops /p/ and /b/ in different vowel contexts. The lip movements were recorded and analysed with the ELITE system. The spatial and temporal characteristics (duration, displacement and velocity) of the symmetric /'VCV/ sequences, where C = /p, b/ and V=/a, i, u/, were analysed. The data show that the main effects of the voiced-voiceless contrast on the bilabial closure movement are a greater degree of lip compression and a greater closure velocity for /p/ than /b/. The effect of the flanking vowels is evident in the different closure duration of the upper and lower lips and in the different closure velocity of the lower lip. Moreover, the time interval between the peak velocity and the peak closure is not affected by neither the voiced-voiceless contrast nor by the vowel context.
Bibliographic reference. Magno Caldognetto, Emanuela / Vagges, Kyriaki / Ferrigno, Giancarlo / Zmarich, Claudio (1993): "Articulatory dynamics of lips in Italian /'vpv/ and /'vbv/ sequences", In EUROSPEECH'93, 409-412.