Photodetector assessment of velopharyngeal activity.

Five normal speakers were used to test a novel photodetector apparatus for obtaining continuous and instantaneous recordings of velopharyngeal area during speech. The results indicate that this inexpensive instrument is able to "track" changes in velopharyngeal port size. A high correlation was found between photodetector output and velopharyngeal port size, as determined using pressure-flow measurements. Its potential use in conjunction with nasopharyngoscopic assessment and in biofeedback training is discussed.