Duration of vocal effects due to water resistance therapy

Abstract

There are only few data about effects of semi-occluded vocal tract exercises on vocal fold oscillation patterns in vivo. Furthermore, it has not yet been clarified for how long these effects last. Material: 16 subjects (8 non-pathological and 8 with vocal fold mass lesion) were asked to sustain a phonation on the vowel /i/. During phonation, the subjects were simultaneously recorded with transnasal high speed videoendoscopy (HSV, 20.000 fps), electroglottography, and audio signals. After that, these subjects performed a Water Resistance Therapy (WRT) for 10 min (tube 30 cm, 9 mm diameter, 5 cm below surface). Repeated measurements of sustained phonation were performed 0, 10, and 30 min after exercising. The data showed strong inter-individual differences concerning the courses of the different measures after WRT. For non-pathological voices, directly after WRT there was a lowering of the Glottal-Area-Waveform derived Period-Perturbation -Quotient, a lowering of the closing quotient. For pathological voices, however, such a decrease was not observable. Five minutes after the exercise such effect was not observable any more. WRT showed strong inter-individual effects in the courses of the evaluated measures. General tendencies of some measures directly after the intervention showed a brief effect of only a few minutes.