Voice Therapy With a Semi-occluded Vocal Tract

Study Overview
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Brief Summary
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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. 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.

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

Conditions
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Voice Disorders

Intervention / Treatment
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* Behavioral: Straw phonation in air
* Behavioral: straw phonation in water
* Behavioral: /u/ phonation


Participation Criteria
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Eligibility Criteria
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Patients: Inclusion criteria are aged between 18 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 criteraia are aged between 18 and 50 years. Exclusion criteria dagnosed with dysphonia, previous or current participation in voice therapy, previous phonosurgical interventions, pregnancy, smoking, nasal or ear diseases, and neurological disorders.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: straw phonation in air<br>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<br>* Phonation (/u/ vowel) through a stirring straw (3 mm diameter, 20cm length) in air<br>* Other names: steady SOVT exercise;|
| Experimental: straw phonation in 2 cm water<br>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<br>* Phonation (/u/ vowel) through a stirring straw (3 mm diameter, 20cm length) in 2 cm or 5 cm water<br>* Other names: water-resistance therapy, fluctuating SOVT exercise;|
| Experimental: straw phonation in 5 cm water<br>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<br>* Phonation (/u/ vowel) through a stirring straw (3 mm diameter, 20cm length) in 2 cm or 5 cm water<br>* Other names: water-resistance therapy, fluctuating SOVT exercise;|
| Active Comparator: /u/ control condition<br>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<br>* /u/ phonation without a straw, control condition<br>* Other names: articulatory/steady SOVT exercise;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| (supra)glottic activity | Laryngeal function determined with the VALI form (Poburka et al., 2017) | baseline (before the intervention), 1 month (immediately after the intervention), 1 month follow-up, 3 months follow-up | 

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. | 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) | AVQI: A lower index indicates a better voice quality. | 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. | 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. | 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. | baseline (before the intervention), 1 month (immediately after the intervention), 1 month follow-up, 3 months follow-up | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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voice, semi-occluded vocal tract, larynx, randomized controlled trial, efficacy study