Voice Therapy With a Semi-occluded Vocal Tract

University Ghent58 enrolled

Overview

1. The first objective of this research is to investigate the immediate effects of three semi-occluded vocal tract (SOVT) exercises (straw phonation in air, straw phonation in 2cm water, and straw phonation in 5cm water) on (supra)glottic activity of vocally healthy participants and patients with voice disorders (dysphonia) visualized with laryngovideostroboscopy. Participants will receive a flexible laryngovideostroboscopy, both during normal phonation and during the specific SOVT exercise. These videos will be randomly and blindly evaluated by two experts using the Voice-Vibratory Assessment with Laryngeal Imaging (VALI) rating form (Poburka et al., 2017). Researchers will compare the effects of these SOVT exercises on the (supra)glottic activity with the effects found in a control group producing /u/ phonation, using a randomized controlled trial. 2. The second objective of this research is to investigate the short- and long-term effects of the three SOVT therapy approaches on the (supra)glottic activity, voice quality and self-report of patients with voice disorders (dysphonia). Participants will receive a short-term intensive therapy with the specific SOVT exercise across four weeks. Immediately after the therapy program and at 1 and 3 months follow-up, the voice of the participants will be re-evaluated.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

Conditions

Voice Disorders

Outcomes

Primary Outcomes

(Supra)Glottic Activity: Amplitude of Vibration

Laryngeal function determined with the Voice-Vibratory Assessment with Laryngeal Imaging (VALI) rating form (Poburka et al., 2017). Amplitude of vibration: magnitude of lateral movement of the vocal folds. This is a visual-perceptual evaluation based on the video samples of the strobovideolaryngoscopy. Raters score the magnitude of lateral movement of the vocal folds based on the graphic of the VALI form ranging from 0 to 10, this number is then multiplied by 10 to obtain a percentage. Lower percentages mean a smaller amplitude of vibration, higher percentages mean a larger amplitude of vibration.

Time frame: baseline (before the intervention)

Supraglottic Activity: Anteroposterior Compression

Laryngeal function determined with the VALI form (Poburka et al, 2017). Anteroposterior supraglottic compression: constriction of the supraglottic structures in the anteroposterior dimension. This is a visual-perceptual evaluation based on the video samples of the strobovideolaryngoscopy. Raters score the supraglottic compression based on the graphic of the VALI form on a scale ranging from 0 to 5 (with the aid of concentric circles). The higher the number, the more supraglottic compression. More supraglottic compression is often seen as a negative outcome, however it might be a beneficial effect seen in SOVT phonation studied here.

Time frame: baseline (before the intervention)

Secondary Outcomes

Voice Quality Index 1: Dysphonia Severity Index (DSI)

DSI: A higher index indicates a better voice quality. The index ranges from -5 to +5 for severely dysphonic to normal voices. A more negative index indicates a worse voice quality. Values \> +5 are possible in subjects with excellent vocal capacities. A DSI = +1.6 is the threshold separating normophonic from dysphonic persons.