Clinical Applications of Facial Sensor Biofeedback: Implications for Voice Therapy or Vocal Training

Abstract

Objectives: Biofeedback therapy is a training technique that has a positive effect on the voice. In order to conduct resonant voice therapy or tube phonation more effectively, it is important for the patient to feel the vibration sensation in a specific part of the facial structures. Therefore, in this study, the clinical basis for facial vibration was presented by quantifying the vibration site and magnitude using vibration sensors during various semi-occluded vocal tract phonations.Methods: A total of 38 normal young adults without dysphonia participated in this study. Recording was performed a total of 6 times for each type of phonation, in the order of /a/ phonation, Kazoo, lip trill, humming, straw phonation, and tube phonation in water at the comfortable level using newly developed facial vibration sensor.Results: There was a significant difference in the magnitude of vibration according to body parts (cheek, nose, neck) during resonant voice or tube phonation; the largest amplitude presented in the nose during humming whereas lip trill, straw, kazoo, and tube phonation in water presented in the cheek. There were also significant differences in the magnitude of vibration among the voice therapy exercises or vocal training techniques (/a/ phonation, Kazoo, lip trill, humming, straw phonation, and tube phonation in water; with greater amplitude in dual sources such as lip trill and water resistance phonation than in single source phonations.Conclusion: The facial vibration sensor could provide clinical evidence for facial vibration sensation during semi-occluded vocal tract phonation. It can also provide biofeedback and monitor whether patients can perform semi-occluded vocal tract phonation properly.