Usability of Vibro-tactile Stimulation to Treat Spasmodic Dysphonia

May 29, 2026 updated by: Juergen Konczak, University of Minnesota

Usability of Laryngeal Vibro-tactile Stimulation as a Non-invasive Treatment for the Voice Disorder Spasmodic Dysphonia

The general aim of the study was to provide evidence for the usability and feasibility of applying vibro-tactile stimulation (VTS) at home as a non-invasive form of neuromodulation to improve speech in people with spasmodic dysphonia (laryngeal dystonia). This work addresses a clinical need to develop alternative or auxiliary treatments for a rare voice disorder with limited treatment options.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Participants with either adductor or abductor-type of spasmodic dysphonia applied VTS at home for a period of 2 months. During the first four weeks they gradually increased their weekly dosage from 3 to 6 days per week. Each application per day lasted 20 minutes.

Study Type

Interventional

Enrollment (Actual)

40

Phase

  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Minnesota
      • Minneapolis, Minnesota, United States, 55414
        • University of Minnesota

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Diagnosis of spasmodic dysphonia (laryngeal dystonia) for a minimum of 6 months with documented symptom relief after Botox injection.
  • Diagnosis is made by a voice disorder specialist.

Exclusion Criteria:

  • Regular intake of benzodiazepines
  • Cognitive impairment: score < 27 on Mini-mental state examination
  • Identifies with a neurological or musculoskeletal impairment affecting speech motor function. These impairments may include a form of: Dyskinesia, Dystonia, Essential Tremor, Huntington's Disease, Multiple System Atrophy, Muscle Tension Dysphonia, Parkinsonism, Progressive Supranuclear Palsy, Spasticity, Intracranial Neoplasm (brain tumor), Spinal Neoplasm, Cerebrovascular Accident (Stroke), Mild Traumatic Brain Injury, Intracranial Hemorrhage, Multiple Sclerosis

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Intervention
Laryngeal vibro-tactile stimulation
Device: Vibro-tactile stimulation
Participants received vibro-tactile stimulation (VTS) as a non-invasive treatment option. Stimulators were a pair of light-weight encapsulated cylindrical vibrators applied to both sides of the larynx (voice box). The vibration frequency for VTS was set be to 100Hz. During VTS, participants feel a mild tingling or vibrating sensation at their larynx. They applied VTS at home over a period of 8 weeks with a daily dosage of 20 minutes. During weeks 1-4, the weekly dosage of VTS was gradually increased (week 1: 3 days/wk; week 2: 4 days/wk; week 3: 5 days/wk; week 4: 6 days/wk). During weeks 5-8, participants applied VTS on self-selected days as needed, not exceeding 6 times a week.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Perceived Speech Effort (PSE) at Week 4
Time Frame: Week 4
Perceived Speech Effort was self-rated by participants on a 0-10 scale (0 = no effort, 10 = maximum effort) while reading standardized sentences at habitual pitch and loudness. Ratings were collected immediately before and after each vibro-tactile stimulation session. The PSE value reported here reflects the group mean at week 4.
Week 4
Perceived Speech Effort (PSE) at Week 8
Time Frame: Week 8
Perceived Speech Effort was self-rated by participants on a 0-10 scale (0 = no effort, 10 = maximum effort) while reading standardized sentences at habitual pitch and loudness. Ratings were collected immediately before and after each vibro-tactile stimulation session. The PSE value reported here reflects the group mean at week 8.
Week 8
Voice Quality Change (VQC) at Week 1
Time Frame: Week 1
Voice Quality Change (VQC) was self-assessed using a 5-point Likert scale (1 = very unnoticeable, 5 = very noticeable; 3 = neutral). Ratings were recorded at the end of each VTS session. VQC at week 1 represents a baseline measure of symptom severity. It was computed as the mean of the first three sessions of VTS of the study.
Week 1
Voice Quality Change (VQC) at Week 8
Time Frame: Week 8
Voice Quality Change (VQC) was self-assessed using a 5-point Likert scale (1 = very unnoticeable, 5 = very noticeable; 3 = neutral). Ratings were recorded at the end of each VTS session. The score reflects the overall longitudinal change in symptoms experienced after treatment end. VQC at week 8 was computed as the mean of the last three sessions of the study.
Week 8

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Relative Change in Perceived Speech Effort (rPSE) for VTS Application Method
Time Frame: 8 weeks
Relative change in PSE (rPSE) was calculated as [(Post - Pre) / Pre] × 100. The between-group difference in mean rPSE comparing VTS received during direct skin contact vs. VTS collar was assessed over the total study period of 8 weeks to understand if the VTS applied directly to the skin was more effective in reducing speech effort than VTS applied via the collar.
8 weeks
Adherence Rate (Feasibility)
Time Frame: Week 1-4
Number of participants who completed at least 80% of prescribed VTS sessions during the intervention period. Thirty out of 32 participants (93.75%) met this adherence threshold
Week 1-4

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Minnesota

Collaborators

National Spasmodic Dysphonia Association

Investigators

  • Principal Investigator: Juergen Konczak, PhD, University of Minnesota

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 21, 2023

Primary Completion (Actual)

October 28, 2024

Study Completion (Actual)

October 31, 2024

Study Registration Dates

First Submitted

October 16, 2023

First Submitted That Met QC Criteria

October 29, 2023

First Posted (Actual)

November 1, 2023

Study Record Updates

Last Update Posted (Actual)

June 25, 2026

Last Update Submitted That Met QC Criteria

May 29, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • STUDY00019659

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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