Change in levator veli palatini muscle activity of normal speakers in association with elevation of the velum using an experimental palatal lift prosthesis.

Abstract Objective: The purpose of this study was to examine whether mechanical elevation of the velum can directly affect the levator veli palatini muscle (LVP) activity using normal speakers as subjects. Design: Each subject was instructed to produce /mu/, /u/, /pu/, /su/, and /tsu/ in a speech task and to blow with maximum possible effort. Smoothed electromyographic activity of the LVP was recorded with an experimental palatal lift prosthesis (PLP) both in place and removed. Participants: Four normal speakers were used as subjects. Results: LVP activity for all tasks was significantly smaller (p < .001; Student's t test) with the PLP in place than without the PLP for all subjects. An analysis of variance (p < .001) clarified that activity ranges of the LVP were significantly different between the removal and placement conditions for all the subjects. Conclusion: The result was similar to that previously obtained for patients with velopharyngeal incompetence wearing a PLP. It is possible that the decrea...