The Effects of Respiratory Training on Voice

The Effects of Respiratory-Based Treatment for Muscle Tension Dysphonia: A Randomized Controlled Trial

Primary muscle tension dysphonia is a voice disorder that involves excessive and poorly coordinated muscle activity affecting multiple subsystems that are involved in speech production, in the absence of structural or neurologic abnormalities of the larynx. Primary muscle tension dysphonia (MTD) is one of the most common forms of voice disorders, accounting for at least 40% of patients seen in voice clinics. Perceptually the voice sounds hoarse and strained, with reduced loudness and pitch range, and people with MTD find speaking very effortful and fatiguing. The physiological abnormalities that characterize MTD are considered multifactorial, and include over-activity of muscles in and around the larynx, laryngeal constriction patterns, and abnormal speech breathing patterns. However, standard treatment approaches for MTD primarily address laryngeal function, including repositioning of laryngeal structures, reducing activity in the intrinsic and extrinsic laryngeal muscles, and altering vibratory patterns. Although voice improvement may follow these treatments, many people with MTD show recurrence of voice problems after only a few months, and some do not improve with treatment. These findings highlight the need for alternative treatments that address the respiratory contributions to MTD, which directly affect the phonatory system. The goal of this project is to compare the effects of two respiratory-based training conditions in people with MTD. A randomized group design will be implemented to determine the respiratory and acoustic effects of each condition. We will determine the effects of each condition immediately after and then 3 and 6 months after training completion to assess short- and long-term training effects. We propose that respiratory training will have a positive effect on related laryngeal behavior and voice. The proposed project has the potential to substantially advance the evidence-based treatment options for MTD, providing a vital step toward reducing the debilitating effects of this disorder.

Study Overview

• Status: Completed
• Conditions: Muscle Tension Dysphonia
• Intervention / Treatment: Behavioral: Breathing training with a device; Behavioral: Breathing training without a device

• Study Type: Interventional
• Enrollment (Actual): 27
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New York
    • Syracuse, New York, United States, 13244
      • Syracuse University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Ages 18 or older
• Self-report of general good health other than voice disorder
• Self-report of normal pulmonary function
• Non-smoker status for at least the last 5 years
• English as their primary language to avoid potential linguistically-based differences in acoustic measures of voice
• Adequate visual acuity (with or without corrective lenses) to read basic graphs and print, as determined with visual screening
• No evidence of current organic or neurologic laryngeal pathology, as assessed by nasolaryngoscopy examination and reviewed by a laryngologist
• No prior surgery to the vocal folds
• Do not report difficulty with swallowing
• Not currently receiving voice therapy or other voice treatment that cannot be discontinued
• Do not report a bilateral, severe to profound hearing loss
• Willingness to be recorded for data collection that is necessary for this study
• Have a confirming diagnosis of Muscle Tension Dysphonia from an otolaryngologist and speech-language pathologist
• Demonstrate quantified auditory-perceptual dysphonia and acoustic dysphonia (Cepstral/Spectral Index of Dysphonia) that exceed normative values for the participant's age and sex
• Based on the nasolaryngoscopy examination and assessment performed by the otolaryngologist, show one or more patterns of supraglottic activity that are consistent with adducted vocal fold hyperfunction
• Show no evidence of abnormal, incomplete vocal fold closure patterns as determined on the videostroboscopy assessment (patterns of posterior glottal gaps are normal and expected)
• Show no evidence of additional neurological voice disorders such as spasmodic dysphonia or vocal fold paralysis
• Show elevated hyolaryngeal position that exceeds normative expectations as determined through quantitative analysis of ultrasonographic laryngeal images measuring change from rest to phonation
• Demonstrate voice problems that have persisted for ≥2 months
• Demonstrate self-reported increase in speaking effort
• Show evidence of speech breathing abnormalities relative to accepted normative values

Exclusion Criteria:

• Ages 17 or younger
• Self-report of major health problems
• Self-report of pulmonary disease such as asthma, chronic obstructive pulmonary disease, or emphysema
• Current smoker status or prior smoker status within the last 5 years
• English not the primary language
• Inadequate visual acuity (with corrective lenses if applicable) to read basic graphs and print as determined by failing a visual screening
• Evidence of current organic or neurologic laryngeal pathology, as assessed by nasolaryngoscopy examination and reviewed by a laryngologist
• Prior surgery to the vocal folds
• Currently receiving voice therapy or other voice treatment that cannot be discontinued
• Self-report of a bilateral, severe to profound hearing loss
• Not willing to be recorded for data collection that is necessary for this study
• No confirming diagnosis of Muscle Tension Dysphonia from an otolaryngologist and speech-language pathologist
• Do not demonstrate quantified auditory-perceptual dysphonia and acoustic dysphonia (Cepstral/Spectral Index of Dysphonia) that exceed normative values for the participant's age and sex
• Based on the nasolaryngoscopy examination and assessment performed by the otolaryngologist, do not show one or more patterns of supraglottic activity that are consistent with adducted vocal fold hyperfunction
• Show evidence of abnormal, incomplete vocal fold closure patterns as determined on the videostroboscopy assessment (patterns of posterior glottal gaps are normal and expected)
• Show evidence of additional neurological voice disorders such as spasmodic dysphonia or vocal fold paralysis
• Do not show elevated hyolaryngeal position that exceeds normative expectations as determined through quantitative analysis of ultrasonographic laryngeal images measuring change from rest to phonation
• Demonstrate voice problems that have persisted for less than 2 months
• Do not demonstrate self-reported increase in speaking effort
• Do not show evidence of speech breathing abnormalities relative to accepted normative values

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Breathing training with a device (Sham Training as Control); Respiratory intervention delivered once a week for 6 weeks, after two initial baseline testing sessions. Participants will perform exhalation exercises through a breathing device. Homework activities will be assigned. Post-training testing sessions will also be conducted.	Behavioral: Breathing training with a device; Breathing training with a mouth device
Active Comparator: Breathing training without a device (Respiratory Lung Volume Training); Respiratory intervention delivered once a week for 6 weeks, after two initial baseline testing sessions. Participants will receive training on the use of breathing techniques without a device, but with visual feedback throughout training. Homework activities will be assigned. Post-training testing sessions will also be conducted.	Behavioral: Breathing training without a device; Breathing training without a mouth device

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Post Training Lung Volume Initiation	Average level of lung volume at which speech breaths are initiated, expressed in percent vital capacity relative to resting expiratory level.	Assessed after completion of 6-week training period, approximately 7 weeks after baseline assessment
Post Training Lung Volume Termination	Average level of lung volume at which speech breaths are terminated, expressed in percent vital capacity relative to resting expiratory level.	Assessed after completion of 6-week training period, approximately 7 weeks after baseline assessment
Post Training Lung Volume Excursion	Average level of lung volume at which speech breaths are terminated, expressed in percent vital capacity.	Assessed after completion of 6-week training period, approximately 7 weeks after baseline assessment
Post Training Cepstral Peak Prominence	Average energy in first cepstral peak relative to overall cepstral energy, measured in cepstral decibels. The Cepstral Peak Prominence measure indicates the regularity, or periodicity, of the voice, and is calculated from the recorded acoustic voice signal. A low score such as 2.0 indicates lower regularity in the voice, or greater severity of voice disturbance, whereas a higher score indicates greater regularity in the voice, or less severity of voice disturbance. The values of this measure can theoretically range from zero to any positive integer value.	Assessed after completion of 6-week training period, approximately 7 weeks after baseline assessment
Post Training Cepstral/Spectral Index of Dysphonia	The Cepstral/Spectral Index of Dysphonia is a multivariate measure that indicates the acoustic severity of voice, and is calculated from the recorded acoustic voice signal. The scale generally ranges from 0 to 100, although negative values and values greater than 100 are possible. A score of zero or a low score indicates no acoustic dysphonia (no voice abnormality) or little dysphonia, whereas a high score or score of 100 indicates high severity or maximal severity of acoustic dysphonia.	Assessed after completion of 6-week training period, approximately 7 weeks after baseline assessment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Post Training Auditory-Perceptual Overall Severity of Voice Disorder	Auditory-Perceptual Overall Voice Severity is a measure that indicates the perceptual severity of the voice, and is determined by listeners who rate the overall severity of how the voice sounds on a Visual Analog Scale that ranges from 0 to 100. A score of zero or a low score indicates no or little perceived dysphonia (voice abnormality), whereas a high score or score of 100 indicates high or maximal perceived severity of dysphonia.	Assessed after completion of 6-week training period, approximately 7 weeks after baseline assessment
Post Training Voice Handicap Index-10	The Voice Handicap Index-10 is a questionnaire in which the participant rates the amount of handicap they feel from their voice disorder. Each of 10 questions is rated between a score of 0 (no handicap) to 4 (extreme handicap). Total scores on this questionnaire can range between 0 to 40, with a low score indicating that the participant feels low amounts of handicap or life impact from their voice disorder, whereas a high score indicates that a participant feels high amounts of handicap from their voice disorder.	Assessed after completion of 6-week training period, approximately 7 weeks after baseline assessment

Collaborators and Investigators

• Sponsor: Syracuse University
• Investigators: Principal Investigator: Soren Y Lowell, PhD, Syracuse University

Study record dates

Study Major Dates

• Study Start (Actual): May 12, 2021
• Primary Completion (Actual): August 29, 2024
• Study Completion (Actual): September 23, 2024

Study Registration Dates

• First Submitted: November 30, 2020
• First Submitted That Met QC Criteria: January 12, 2021
• First Posted (Actual): January 15, 2021

Study Record Updates

• Last Update Posted (Actual): July 24, 2025
• Last Update Submitted That Met QC Criteria: July 3, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: treatment; training; respiratory; voice; voice disorder; muscle tension dysphonia
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Respiratory Tract Diseases; Respiration Disorders; Otorhinolaryngologic Diseases; Signs and Symptoms, Respiratory; Laryngeal Diseases; Voice Disorders; Dysphonia; Hoarseness
• Other Study ID Numbers: 20-132

Drug and device information, study documents

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