THE ROLE OF LIP AND TONGUE ARTICULATION FOR SWEDISH VOWELS A perception study with articulatory synthesis

Abstract

This study uses a novel approach that combines articulatory synthesis with a perception experiment to explore the role of individual articulators in Swedish long vowels, particularly lip and tongue articulation concerning the front, close vowels /i/, /y/ and /ʉ/. These vowels are perceptually close and determining the important articulatory features is not straightforward, since both the lips and the tongue may contribute to the contrasts. Isolated vowel sounds were created with the help of articulatory synthesis and articulatory data from one male and one female Swedish speaker. The vowels /i:/, /y:/ and /ʉ:/ were manipulated so that each sound appeared with their own tongue configuration but with one of the other vowels’ lip configuration. All nine long vowels of Swedish appeared with their original articulatory configuration and with the lip section removed. The vowels were analyzed acoustically and implemented in a perception experiment, where Swedish listeners categorized them. For the /i:/ - /y:/-contrast, lip configuration seemed to be the most important articulatory feature. For one of the speakers, it was possible to alternate between all three vowels /i/, /y/ and /ʉ/ just by a change of lip configuration, which is suggested to be connected to the individual speaker’s location of tongue constriction. The speakers’ tongue articulation of /ʉ/ differed to the other front close vowels and they were not interchangeable. Removing the lip section altogether had perceptual consequences, especially for rounded vowels