Abstract

Therapeutic Effect of Semi-Occluded Vocal Tract Exercises in Patients with Type I Muscle Tension Dysphonia Phonation with semi-occluded postures of the vocal tract and phonation into resonance tubes are widely used for the purpose of voice therapy and voice training. These techniques increase the source/filter interaction and produce several physiologic and acoustic effects such as an increase of the inertive reactance of the vocal tract in the 200-1000 Hz range and thereby reinforce vocal fold vibration. Eleven male and female acting students diagnosed with type I Muscle tension dysphonia were treated with a sequence of semi-occluded vocal tract exercises during six sessions. This sequence included a prolonged bilabial consonant /B/and artificial lengthening of the vocal tract using resonance tubes. Phonatory tasks performed were a sustained phonation in a comfortable pitch, and ascending/descending pitch glides. Voice samples were recorded before and six sessions after voice therapy. Flexible laryngoscopy and spectral analysis using a spectrogram with a narrow filter at real time were used for analysis. Spectrograms were evaluated by five blind judges on a 100 mm visual analogue scale. Two time points were compared and statistical analysis performed. Significant positive changes were observed by spectral analysis evaluation but with no clear laryngeal muscle pattern changes. The result indicates that the use of resonance tubes and semioccluded postures of the vocal tract can have a therapeutic effect in patients with type I Muscle tension dysphonia.