Trial Outcomes & Findings for The Effects of Respiratory Training on Voice (NCT NCT04710862)

NCT ID: NCT04710862

Last Updated: 2025-07-24

Results Overview

Average level of lung volume at which speech breaths are initiated, expressed in percent vital capacity relative to resting expiratory level.

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 27 participants
• Primary outcome timeframe: Assessed after completion of 6-week training period, approximately 7 weeks after baseline assessment
• Results posted on: 2025-07-24

Participant Flow

27 participants were enrolled in the study. After initial testing to determine inclusion and exclusion criteria, 3 participants were excluded due to not meeting all inclusion/exclusion criteria. The remaining 24 participants were randomized into the two intervention groups, 12 per group.

Participant milestones

Measure	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. Breathing training with a device: Breathing training with a mouth device	Breathing Training Without a Device 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. Breathing training without a device: Breathing training without a mouth device
Overall Study STARTED	12	12
Overall Study COMPLETED	12	12
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

The Effects of Respiratory Training on Voice

Baseline characteristics by cohort

Measure	Breathing Training With a Device (Sham Training as Control) n=12 Participants 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. Breathing training with a device: Breathing training with a mouth device	Breathing Training Without a Device (Respiratory Lung Volume Training) n=12 Participants 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. Breathing training without a device: Breathing training without a mouth device	Total n=24 Participants Total of all reporting groups
Age, Continuous	60.0 years STANDARD_DEVIATION 15.4 • n=5 Participants	55.4 years STANDARD_DEVIATION 12.6 • n=7 Participants	58.3 years STANDARD_DEVIATION 13.9 • n=5 Participants
Sex: Female, Male Female	7 Participants n=5 Participants	5 Participants n=7 Participants	12 Participants n=5 Participants
Sex: Female, Male Male	5 Participants n=5 Participants	7 Participants n=7 Participants	12 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	0 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	12 Participants n=5 Participants	11 Participants n=7 Participants	23 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) White	12 Participants n=5 Participants	11 Participants n=7 Participants	23 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Region of Enrollment United States	12 participants n=5 Participants	12 participants n=7 Participants	24 participants n=5 Participants
Lung Volume Initiation - Relative to Resting Expiratory Level	19.01 % vital capacity relative to rest level STANDARD_DEVIATION 6.11 • n=5 Participants	15.05 % vital capacity relative to rest level STANDARD_DEVIATION 7.00 • n=7 Participants	17.03 % vital capacity relative to rest level STANDARD_DEVIATION 6.56 • n=5 Participants
Lung Volume Termination - Relative to Resting Expiratory Level	-1.07 % vital capacity relative to rest level STANDARD_DEVIATION 4.40 • n=5 Participants	-4.55 % vital capacity relative to rest level STANDARD_DEVIATION 5.38 • n=7 Participants	-2.81 % vital capacity relative to rest level STANDARD_DEVIATION 4.89 • n=5 Participants
Lung Volume Excursion	20.08 % vital capacity relative to rest level STANDARD_DEVIATION 4.94 • n=5 Participants	19.60 % vital capacity relative to rest level STANDARD_DEVIATION 8.04 • n=7 Participants	19.84 % vital capacity relative to rest level STANDARD_DEVIATION 6.49 • n=5 Participants
% Vital Capacity per Syllable	1.42 % vital capacity relative to rest level STANDARD_DEVIATION 0.48 • n=5 Participants	1.44 % vital capacity relative to rest level STANDARD_DEVIATION 0.65 • n=7 Participants	1.43 % vital capacity relative to rest level STANDARD_DEVIATION 0.57 • n=5 Participants
Cepstral/Spectral Index of Dysphonia	30.73 units on a scale STANDARD_DEVIATION 13.18 • n=5 Participants	29.59 units on a scale STANDARD_DEVIATION 8.43 • n=7 Participants	30.16 units on a scale STANDARD_DEVIATION 10.81 • n=5 Participants
Cepstral Peak Prominence	4.96 decibels (dB) STANDARD_DEVIATION 1.24 • n=5 Participants	4.85 decibels (dB) STANDARD_DEVIATION 0.96 • n=7 Participants	4.91 decibels (dB) STANDARD_DEVIATION 1.10 • n=5 Participants
Auditory-Perceptual Overall Voice Severity	35.16 units on a scale STANDARD_DEVIATION 24.40 • n=5 Participants	30.85 units on a scale STANDARD_DEVIATION 20.71 • n=7 Participants	33.01 units on a scale STANDARD_DEVIATION 22.56 • n=5 Participants
Speaking Effort	56.56 units on a scale STANDARD_DEVIATION 22.43 • n=5 Participants	58.46 units on a scale STANDARD_DEVIATION 13.99 • n=7 Participants	57.51 units on a scale STANDARD_DEVIATION 18.21 • n=5 Participants
Voice Handicap Index-10	19.96 units on a scale STANDARD_DEVIATION 6.49 • n=5 Participants	19.75 units on a scale STANDARD_DEVIATION 9.33 • n=7 Participants	19.86 units on a scale STANDARD_DEVIATION 7.91 • n=5 Participants

PRIMARY outcome

Timeframe: Assessed after completion of 6-week training period, approximately 7 weeks after baseline assessment

Average level of lung volume at which speech breaths are initiated, expressed in percent vital capacity relative to resting expiratory level.

Outcome measures

Measure	Breathing Training With a Device (Sham Training as Control) n=12 Participants 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. Breathing training with a device: Breathing training with a mouth device	Breathing Training Without a Device (Respiratory Lung Volume Training) n=12 Participants 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. Breathing training without a device: Breathing training without a mouth device
Post Training Lung Volume Initiation	21.07 % vital capacity relative to rest level Standard Deviation 4.94	27.04 % vital capacity relative to rest level Standard Deviation 7.71

PRIMARY outcome

Timeframe: Assessed after completion of 6-week training period, approximately 7 weeks after baseline assessment

Average level of lung volume at which speech breaths are terminated, expressed in percent vital capacity relative to resting expiratory level.

Outcome measures

Measure	Breathing Training With a Device (Sham Training as Control) n=12 Participants 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. Breathing training with a device: Breathing training with a mouth device	Breathing Training Without a Device (Respiratory Lung Volume Training) n=12 Participants 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. Breathing training without a device: Breathing training without a mouth device
Post Training Lung Volume Termination	-0.44 % vital capacity relative to rest level Standard Deviation 5.26	2.29 % vital capacity relative to rest level Standard Deviation 5.04

PRIMARY outcome

Timeframe: Assessed after completion of 6-week training period, approximately 7 weeks after baseline assessment

Average level of lung volume at which speech breaths are terminated, expressed in percent vital capacity.

Outcome measures

Measure	Breathing Training With a Device (Sham Training as Control) n=12 Participants 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. Breathing training with a device: Breathing training with a mouth device	Breathing Training Without a Device (Respiratory Lung Volume Training) n=12 Participants 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. Breathing training without a device: Breathing training without a mouth device
Post Training Lung Volume Excursion	21.51 % vital capacity Standard Deviation 4.81	24.74 % vital capacity Standard Deviation 6.48

PRIMARY outcome

Timeframe: Assessed after completion of 6-week training period, approximately 7 weeks after baseline assessment

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.

Outcome measures

Measure	Breathing Training With a Device (Sham Training as Control) n=12 Participants 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. Breathing training with a device: Breathing training with a mouth device	Breathing Training Without a Device (Respiratory Lung Volume Training) n=12 Participants 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. Breathing training without a device: Breathing training without a mouth device
Post Training Cepstral Peak Prominence	4.86 decibels (dB) Standard Deviation 1.10	5.31 decibels (dB) Standard Deviation 0.81

PRIMARY outcome

Timeframe: Assessed after completion of 6-week training period, approximately 7 weeks after baseline assessment

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.

Outcome measures

Measure	Breathing Training With a Device (Sham Training as Control) n=12 Participants 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. Breathing training with a device: Breathing training with a mouth device	Breathing Training Without a Device (Respiratory Lung Volume Training) n=12 Participants 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. Breathing training without a device: Breathing training without a mouth device
Post Training Cepstral/Spectral Index of Dysphonia	29.03 units on a scale Standard Deviation 14.06	21.96 units on a scale Standard Deviation 9.76

SECONDARY outcome

Timeframe: Assessed after completion of 6-week training period, approximately 7 weeks after baseline assessment

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.

Outcome measures

Measure	Breathing Training With a Device (Sham Training as Control) n=12 Participants 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. Breathing training with a device: Breathing training with a mouth device	Breathing Training Without a Device (Respiratory Lung Volume Training) n=12 Participants 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. Breathing training without a device: Breathing training without a mouth device
Post Training Auditory-Perceptual Overall Severity of Voice Disorder	33.29 units on a scale Standard Deviation 24.18	18.78 units on a scale Standard Deviation 12.28

SECONDARY outcome

Timeframe: Assessed after completion of 6-week training period, approximately 7 weeks after baseline assessment

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.

Outcome measures

Measure	Breathing Training With a Device (Sham Training as Control) n=12 Participants 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. Breathing training with a device: Breathing training with a mouth device	Breathing Training Without a Device (Respiratory Lung Volume Training) n=12 Participants 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. Breathing training without a device: Breathing training without a mouth device
Post Training Voice Handicap Index-10	14.38 units on a scale Standard Deviation 6.63	12.13 units on a scale Standard Deviation 6.02

Adverse Events

Breathing Training With a Device (Sham Training as Control)

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Breathing Training Without a Device (Respiratory Lung Volume Training)

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Soren Lowell

Syracuse University

Phone: 315-443-9615

Email: slowell@syr.edu

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place