Effectiveness of Low-Level Light Therapy for Vocal Fatigue

NCT ID: NCT07062302

Last Updated: 2025-07-14

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

22 participants

Study Classification

INTERVENTIONAL

Study Start Date

2024-03-09

Study Completion Date

2024-06-12

Brief Summary

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The goal of this phase 2 clinical trial is to examine the effectiveness of photobiomodulation in patients with vocal fatigue.

The main question it aims to answer is whether photobiomodulation is able to alleviate vocal fatigue in patients with diagnosed vocal fatigue.

Participants will ask to receive photobiomodulation treatment for 12 sessions over a three week period.

Detailed Description

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Vocal fatigue is a common complaint of patients with voice disorder and is related to functional and/or organic voice disorders. Professional voice users, such as teachers and singers and actors, are particularly prone to vocal fatigue. It has been reported that vocal fatigue also associated with limitation to voice activities and participation. In patients with vocal fatigue, experience of inflammation and muscle pain are among possible symptoms and manifestations of the condition.

In literature, various definitions have been suggested for vocal fatigue. Welham and Maclagan defined vocal fatigue as the negative vocal adaptation led by prolonged use of voice, and it can consist of perceptual, acoustic or physiologic components of undesirable or unexpected functional changes in the laryngeal mechanism.

In exploring the nature of vocal fatigue, Titze capitalised on a generally recognised mechanism of muscle fatigue which comprised of a peripheral component and a central component. Specifically, for the peripheral component, fatigue may take place at the myo-neural junction, muscle membrane and endo-plasmic reticulum (i.e., the transmission mechanism) or the muscle filaments (i.e., the contractile mechanism), where depletion or accumulation of biochemical substances such as glycogen occurs.

Low-level light therapy (LLLT), also known as photobiomodulation (PBM) therapy, has been developed as a therapeutic procedure which involves the exposure to low levels of red and near infrared light to cells or tissues. It has been approved by the Food and Drug Administration (FDA) of the United States for aesthetic and medical purposes.

Ever since, it has been established as a non-invasive and safe approach for a number of medical processes, such as reducing inflammation, relieving pain, wound healing, skeletal muscle repair and treating neurological disorders. Specifically, its effectiveness on treating muscle fatigue was investigated with the focus placed on muscles such as bicep braquialis, quadriceps and orbicularis oris.

These studies utilised the feature of LLLT to interact with muscle tissues and therefore provide physiological and/or therapeutics effects to reduce muscle fatigue and enhance muscle performance. Relating this to the fatigue resulting from prolonged voice use at the laryngeal level, it is possible for LLLT to be developed as a treatment approach for vocal fatigue.

In a Phase 1 study, the potential effectiveness of using LLLT in vocal fatigue treatment by applying red or infrared Lights to healthy individuals following vocal loading tasks was explored. The authors concluded that red light might be effective in improving vocal fatigue on aspects of acoustic, aerodynamic, and self-perceptual markers.

The proposed study will be a Phase 2 behavioural study-controlled trial on the effectiveness of LLLT on treating vocal fatigue.

The primary objective of this study is to investigate the effectiveness of lower-level light therapy on reducing vocal fatigue on self-perceptual phenomena exhibited by participants, as well as acoustic and aerodynamic changes in voice.

Vocal Fatigue Index (Hong Kong-Chinese Version) (VFI(HK)) will be used as the primary outcome measurement methods. Perceptual evaluation of voice, acoustic measurement, aerodynamics evaluation (by maximum phonation time (MPT)), vocal symptoms scale and Voice Handicap Index (VHI-30) will be used as secondary outcome measurements.

The current study will be a preliminary clinical trial to identify the therapeutic efficacy of PBM on laryngeal muscles as a new treatment for patients with vocal fatigue. It could act as a pilot study and results obtained could be a foundation for Phase 3 RCT studies to investigate using LLLT to treat vocal fatigue.

Conditions

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Vocal Fatigue

Study Design

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Allocation Method

NA

Intervention Model

SINGLE_GROUP

Photobiomodulation
Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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Photobiomodulation arm

Group Type EXPERIMENTAL

photobiomodulation

Intervention Type DEVICE

The output of the photobiomodulation device is listed as below:

* Irradiation size: 15 cm × 10 cm
* Dual-wavelength: 660 nm + 850 nm
* Optical power density: 10 - 15 mW/cm2
* Dose density: 6J/cm2

Interventions

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photobiomodulation

The output of the photobiomodulation device is listed as below:

* Irradiation size: 15 cm × 10 cm
* Dual-wavelength: 660 nm + 850 nm
* Optical power density: 10 - 15 mW/cm2
* Dose density: 6J/cm2

Intervention Type DEVICE

Other Intervention Names

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low level light therapy

Eligibility Criteria

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Inclusion Criteria

* Aged over 18 years old
* Meeting the diagnosis of vocal fatigue as per the VFI-HK
* Able to make informed consent
* Have not received any voice therapy before

Exclusion Criteria

* History of photoallergy
* Significant medical or chronic diseases
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Chinese University of Hong Kong

OTHER

Sponsor Role lead

Responsible Party

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Thomas Law

Assistant Professor

Responsibility Role PRINCIPAL_INVESTIGATOR

Locations

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The Chinese University of Hong Kong

Shatin, N.T., Hong Kong

Site Status

Countries

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Hong Kong

References

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Moreno M, Calvache C, Cantor-Cutiva LC. Systematic Review of Literature on Prevalence of Vocal Fatigue Among Teachers. J Voice. 2025 Jan;39(1):105-112. doi: 10.1016/j.jvoice.2022.07.029. Epub 2022 Sep 20.

Reference Type BACKGROUND
PMID: 36137877 (View on PubMed)

Welham NV, Maclagan MA. Vocal fatigue: current knowledge and future directions. J Voice. 2003 Mar;17(1):21-30. doi: 10.1016/s0892-1997(03)00033-x.

Reference Type BACKGROUND
PMID: 12705816 (View on PubMed)

Other Identifiers

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CREC2023.483

Identifier Type: -

Identifier Source: org_study_id

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