N/A N=24 Randomized Double-blind Treatment

The Effects of Respiratory Training on Voice

Muscle Tension Dysphonia

Bottom Line

View on ClinicalTrials.gov: NCT04710862 ↗

Enrolled (actual)

Serious AEs

0.0%

Results posted

Jul 2025

Primary outcome: Primary: Post Training Lung Volume Initiation — 21.07; 27.04 % vital capacity relative to rest level — p=<0.0005

Study Design & Population

Study type: Interventional
Phase: N/A
Interventions: Breathing training without a device (Behavioral); Breathing training with a device (Behavioral)
Age: Adult, Older Adult · 18+ yrs
Sex: All
Sponsor: Syracuse University
Primary completion: Aug 2024

Outcome Measures

Outcome	Result	p-value
PRIMARY Post Training Lung Volume Initiation	21.07; 27.04	<0.0005 sig
PRIMARY Post Training Lung Volume Termination	-0.44; 2.29	<0.0005 sig
PRIMARY Post Training Lung Volume Excursion	21.51; 24.74	0.012 sig
PRIMARY Post Training Cepstral Peak Prominence	4.86; 5.31	0.001 sig
PRIMARY Post Training Cepstral/Spectral Index of Dysphonia	29.03; 21.96	0.004 sig
SECONDARY Post Training Auditory-Perceptual Overall Severity of Voice Disorder	33.29; 18.78	0.001 sig
SECONDARY Post Training Voice Handicap Index-10	14.38; 12.13	0.328

Summary

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.

Eligibility Criteria

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 t

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Data sourced from ClinicalTrials.gov (NCT04710862). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.