Tongue and lower lip movement in semivowel /w/ production

Aims: Previous studies have shown significant correlations between the acoustic characteristics of /w/ and speech intelligibility. To understand the articulatory pattern in /w/ production, the current study investigated the movement characteristics of the tongue and lower lip in whip productions in comparison to bib productions. Methods: Data from 19 typical adult male participants were collected using electromagnetic articulography. A number of kinematic measures of tongue body (approximately 25 mm posterior to the tongue apex) and lower lip movements were analyzed. Results: The findings suggested different movement patterns of the tongue body and lower lip in whip and bib productions. The amount of lip movement in the anterior-posterior plane exhibited by each speaker did not vary between whip and bib. However, speakers did exhibit more tongue retraction/advancement, greater overall tongue movement, and faster tongue movement speed in whip than in bib. Conclusion: Tongue movement in the anterior-posterior plane, such as tongue retraction and advancement, was found to be crucial for the production of /w/ in typical male speakers. Thus, the articulatory kinematics of the tongue in the anterior-posterior plane and its coordination with the lips need to be further examined in speakers with dysarthria to understand the underlying kinematic characteristics that influence speech intelligibility.