Efficacy of Flow Ball Phonation in Professional Voice Users

University Ghent

Status: Enrolling

Conditions: Prevention of Voice Disorders in Professional Voice Users; Treatment of Functional Voice Disorders in Professional Voice Users

Treatments: Behavioral: Straw Phonation Intervention; Behavioral: Flow Ball Intervention; Behavioral: Sham Intervention

Study type: Interventional

Funder types: Other

Identifiers

NCT06960772

ONZ-2025-0017

Details and patient eligibility

About

The aim of this study is to investigate the effects of flow ball phonation on the voice of professional voice users and elite vocal performers, both with and without functional voice disorders. Given the substantial vocal demands inherent to this population and their reliance on the voice for occupational purposes, this intervention may represent a valuable approach for the prevention and/or treatment voice disorders.

Full description

Background. Due to the high vocal demands, professional voice users (e.g. teachers) and elite vocal performers (e.g. singers) are risk populations for developing voice disorders. High-quality voice research in these vulnerable populations is highly needed for effective and efficient treatment and prevention of voice disorders. The flow ball (FB) is a promising innovative voice therapy device to perform semi-occluded vocal tract exercises (SOVTE) with the extra advantage of providing real-time visual feedback of the airflow. Despite this important advantage, strong efficacy studies of an FB intervention program are lacking.

Objective. To investigate the immediate-, short- and long-term effects of an SOVTE intervention with the FB on the phonation of professional voice users with (treatment) and without (prevention) voice disorders and to compare it with the 'treatment as usual' straw phonation (SP) and a sham condition, using a longitudinal randomized sham-controlled trial (RCT).

Methods. Subjects will be randomly assigned into an FB group, an SP group or a control (sham) group. They will receive a short-term intensive voice intervention of 3 weeks, combining both guided therapy/training sessions and independent practice at home. A flexible strobovideolaryngoscopy and a multidimensional voice assessment will be performed by assessors blinded to group allocation and study phase. Assessments will be performed two times before the intervention (pre 1 and pre 2), immediately after the intensive intervention (post 1) and at 3 weeks (follow-up 1) and 3 months (follow-up 2) follow-up. The sham group will use the same FB device but no phonation will be involved.

Enrollment: 144 estimated patients

Sex: All

Ages: 18 to 60 years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

OBJECTIVE 1: TREATMENT

Inclusion Criteria:

• All genders
• All ethnicities
• 18 - 60 years
• Diagnosis of a functional voice disorder
• Professional voice users

Exclusion Criteria:

• Diagnosis of an organic voice disorder
• Current participation in voice therapy
• Previous phonosurgical interventions
• Pregnancy
• Smoking
• Nasal or ear diseases
• Neurological disorders

OBJECTIVE 2: PREVENTION

Inclusion Criteria:

• All genders
• All ethnicities
• 18 - 60 years
• Professional voice users

Exclusion Criteria:

• Current or previous diagnosis of a voice disorder
• Current or previous participation in voice therapy
• Previous phonosurgical interventions
• Pregnancy
• Smoking
• Nasal or ear diseases
• Neurological disorders

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

---

144 participants in 3 patient groups

Flow Ball

Experimental group

Treatment:

Behavioral: Flow Ball Intervention

Straw Phonation

Experimental group

Treatment:

Behavioral: Straw Phonation Intervention

Sham Intervention

Sham Comparator group

Treatment:

Behavioral: Sham Intervention