OBJECTIVE: To verify the effect of the basal sound technique in closure of the velopharyngeal sphincter (VPS) in 5 adult subjects with cleft palate repaired post-foramen and without previous speech-language pathologist treatment. METHODS: The study included 5 subjects who underwent otorhinolaryngological evaluation through nasopharyngoscopy, for image registration and quantification of the VPS closure area, before and after execution of 3 minutes of basal sound technique. During the evaluation, subjects emitted the vowel /a:/ at usual pitch and loudness. Emission of the vowel /a:/ was also used for auditory perceptual evaluation and image generation of acoustic speech patterns (spectrograms) of the voices. The results were analyzed descriptively, according to the number of subjects, which characterizes this work as a case study. RESULTS: Four subjects displayed improved closure regarding area of VPS closure. Spectrographic evaluation revealed reduction of hypernasality. Analysis of the results of auditory perceptual evaluation showed improvement of overall vocal quality, with adequate loudness, decreased hypernasality, improved voice type, and decreased hoarseness. CONCLUSION: The present study indicated positive effects on the voice and VPS closure area after basal sound achievement.