Voice Therapy With a Semi-occluded Vocal Tract

Voice Therapy With a Semi-occluded Vocal Tract: From Current Challenges to Next Level Efficacy Studies

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 Overview

• Status: Completed
• Conditions: Voice Disorders
• Intervention / Treatment: Behavioral: Straw phonation in air; Behavioral: straw phonation in water; Behavioral: /u/ phonation

• Study Type: Interventional
• Enrollment (Actual): 58
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Belgium
  • East-Flanders
    • Ghent, East-Flanders, Belgium, 9000
      • Department of Rehabilitation Sciences, Ghent University (Hospital)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: Yes

Description

Patients:

Inclusion criteria are aged between 17 and 50 years, and diagnosed with dysphonia by an otorhinolaryngologist and SLP experienced in voice diagnostics. Exclusion criteria are previous or current participation in voice therapy, previous phonosurgical interventions, pregnancy, smoking, nasal or ear diseases, and neurological disorders.

Vocally healthy participants:

Inclusion criteria are aged between 17 and 50 years. Exclusion criteria are dagnosed with dysphonia, previous or current participation in voice therapy, previous phonosurgical interventions, pregnancy, smoking, nasal or ear diseases, and neurological disorders.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: straw phonation in air; Participants will be asked to phonate an /u/ vowel through a stirring straw in air with slightly pursed lips and a soft voice onset.	Behavioral: Straw phonation in air; Phonation (/u/ vowel) through a stirring straw (3 mm diameter, 20cm length) in air; Other Names: steady SOVT exercise
Experimental: straw phonation in 2 cm water; Participants will be asked to phonate an /u/ vowel through a stirring straw, placed 2 cm below the water surface, with slightly pursed lips and a soft voice onset.	Behavioral: straw phonation in water; Phonation (/u/ vowel) through a stirring straw (3 mm diameter, 20cm length) in 2 cm or 5 cm water; Other Names: water-resistance therapy, fluctuating SOVT exercise
Experimental: straw phonation in 5 cm water; Participants will be asked to phonate an /u/ vowel through a stirring straw, placed 5 cm below the water surface, with slightly pursed lips and a soft voice onset.	Behavioral: straw phonation in water; Phonation (/u/ vowel) through a stirring straw (3 mm diameter, 20cm length) in 2 cm or 5 cm water; Other Names: water-resistance therapy, fluctuating SOVT exercise
Active Comparator: /u/ control condition; Participants will be asked to phonate an /u/ vowel with slightly pursed lips and a soft voice onset but without a straw.	Behavioral: /u/ phonation; /u/ phonation without a straw, control condition; Other Names: articulatory/steady SOVT exercise

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
(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.	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.	baseline (before the intervention)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	baseline (before the intervention), 1 month (immediately after the intervention), 1 month follow-up, 3 months follow-up
Voice Quality Index 2: Acoustic Voice Quality Index (AVQI)	A lower AVQI indicates a better voice quality. The index ranges from 0 to 10 for normal to severely dysphonic voices. An AVQI of 2.95 is the threshold separating normophonic from dysphonic persons.	baseline (before the intervention), 1 month (immediately after the intervention), 1 month follow-up, 3 months follow-up
Self-report 1: Voice Handicap Index (VHI)	VHI: A lower index indicates less impact of the voice impairment on the quality of life. The VHI ranges from 0 to 120.	baseline (before the intervention), 1 month (immediately after the intervention), 1 month follow-up, 3 months follow-up
Self-report 2: Vocal Tract Discomfort Scale (VTDS)	VTDS: A lower index indicates less discomfort in the vocal tract. The index ranges from 0 to 96.	baseline (before the intervention), 1 month (immediately after the intervention), 1 month follow-up, 3 months follow-up
Self-report 3: Vocal Fatigue Index (VFI)	VFI: A lower index indicates less vocal fatigue. The index ranges from 0 to 76.	baseline (before the intervention), 1 month (immediately after the intervention), 1 month follow-up, 3 months follow-up

Collaborators and Investigators

• Sponsor: University Ghent
• Collaborators: Research Foundation Flanders
• Investigators: Principal Investigator: Kristiane Van Lierde, PhD, University Ghent

Study record dates

Study Major Dates

• Study Start (Actual): October 7, 2021
• Primary Completion (Actual): March 14, 2023
• Study Completion (Actual): March 14, 2023

Study Registration Dates

• First Submitted: October 20, 2023
• First Submitted That Met QC Criteria: November 13, 2023
• First Posted (Actual): November 18, 2023

Study Record Updates

• Last Update Posted (Actual): October 30, 2024
• Last Update Submitted That Met QC Criteria: August 7, 2024
• Last Verified: August 1, 2024

More Information

Terms related to this study

• Keywords: randomized controlled trial; voice; larynx; efficacy study; semi-occluded vocal tract
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Respiratory Tract Diseases; Otorhinolaryngologic Diseases; Laryngeal Diseases; Voice Disorders
• Other Study ID Numbers: 249721N

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No