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Work of BreathingNCT07470099

The Role of Breathing Perception in Respiratory Control

A study testing Ambient Noise, Increased Auditory Feedback and Noise Distraction in people with Work of Breathing, run by Indiana University at 1 site in United States.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial summary

Warfighters are frequently exposed to environments and life-support systems that increase breathing resistance and the work of breathing (WOB), such as aircraft on-board oxygen generation systems and underwater breathing apparatuses. Read more about this study

Who is it for?
Ages 18 to 40 yearsHealthy volunteers can take part
Conditions the study is for
Work of Breathing
What is being tested?
Ambient Noise, Increased Auditory Feedback and Noise Distraction
Could I receive a placebo?
No, everyone receives an active treatment
How many people
15 participants
Where
1 siteUnited States
Study dates
1 Jun 2027to 30 Sep 2028
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 40 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Between the ages of 18-40 years old.
  • English speaking and reading.
  • Self-reported weekly activity of at least 120 minutes/week of high intensity exercise for the previous 2 years.
  • Normal pulmonary function assessed by a resting forced expiratory volume in 1 second over forced vital capacity (FEV1/FVC) > 75% of predicted.
  • Normal cognitive function assessed using the Montreal cognitive function test [18].
  • Body mass index (BMI) ≤ 35 kg/m2.
  • Females with a regular menstrual cycle that ranges from 21-35 days (eumenorrhea)

Who cannot join

  • History of smoking or recreational smoking, cardiovascular disease, renal disease, pulmonary disease (including asthma or exercise-induced asthma), neurological disease, and metabolic disease.
  • Are pregnant or could possibly be pregnant by self-report.
  • Are color blind.
  • Known allergy or hypersensitivity latex.
  • Take selective serotonin reuptake inhibitors, stimulant medication, antibiotics, and chronically consume pain medication (Aleve, Tylenol, etc.).
  • Resting blood pressure of > 130mmHg systolic or 90 mmHg diastolic and/or resting pulse rate of > 100 bpm.
  • Females with irregular menstrual cycles (oligomenorrhea) that ranges from 36-90 days, and females with the absence of a menstrual cycle (amenorrhea).
  • Taking birth control for the sole purpose of period cessation (eg., Mirena IUD)

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Timothy D Mickleborough, PhD contact

812-855-0753

tmickleb@iu.edu

United States1 site
  • Multidisciplinary Engineering and Sciences Hall (MESH)

    Bloomington, Indiana, 47405

    Scott M Clarke, 812-856-3244, scotclar@iu.edu

    Zachary J Schalder, PhD, 812-855-6953, zschlade@iu.edu

Other trials in United States

About this study

Official title: Optimizing Mind-Body Interactions in Respiratory Control During Operationally Relevant Environmental Stressors

Warfighters are frequently exposed to environments and life-support systems that increase breathing resistance and the work of breathing (WOB), such as aircraft on-board oxygen generation systems and underwater breathing apparatuses. Elevated WOB then increases the perception of breathing difficulty (dyspnea) and has been associated with impaired cognitive performance, including slower reaction time and reduced accuracy during attention-demanding tasks. These effects are particularly concerning in operational settings that require rapid decision-making and precise motor responses.

Despite growing recognition of this issue, critical gaps remain regarding strategies to mitigate the perceptual and cognitive consequences of elevated inspiratory resistance, especially under realistic operational stressors. The objective of this experiment is to determine whether modifying the sensory perception of breathing alters breathing perception and cognitive performance during inspiratory resistance. Auditory feedback of ventilation will be manipulated (normal, reduced, or amplified) to assess whether altering breathing-related sensory input affects breathing perception and cognitive performance without changing mechanical load.

Read the detailed description

In some instances, reducing inspiratory resistive loads (e.g., OBOGs, SCUBA) for Warfighters may not be feasible, but understanding how breathing perception is affected by resistance is essential. Auditory feedback of ventilation significantly influences breathing awareness, and as the WOB increases, this perception intensifies due to enhanced auditory input. This heightened awareness can distract and tax cognitive processing. Recent studies indicate that auditory distractions, like music during exercise, can lessen dyspnea and respiratory and whole-body discomfort in healthy individuals and those with chronic obstructive pulmonary disease. This effect may stem from reduced auditory feedback or improved emotional states linked to music. However, a key knowledge gap exists: it is unclear whether reducing auditory feedback of ventilation during increased inspiratory resistance affects breathing perception and cognitive function. The study will assess the impact of different auditory feedback of ventilation conditions (normal, eliminated via noise distraction, and amplified) on cognitive function under high inspiratory resistance. It's hypothesized that reducing auditory feedback of ventilation will not alter the WOB but will decrease breathing perception and enhance cognitive performance compared to standard or amplified feedback.

Participants will complete two study visits: a screening/familiarization visit (Study Day 0) followed by one experimental visit (Study Day 1). Participants will be instructed to avoid caffeine, alcohol, stimulant medication, pain/anti-inflammatory medication, cannabis and cannabis related products, and vigorous exercise for at least 24 hours prior to experimental visits. On Study Day 0, participants will complete a short familiarization breathing task in which they will breathe for 10 minutes through an 8-10mm hole at the end of a customized device, generating a pre-determined inspiratory resistance of 6-9.5 centimeters of water per liter per second (cmH2O/L/s). During the breathing task, cerebral vascular, cardiovascular and autonomic activity responses will be measured. Every 5 minutes during the breathing test, participants will be asked to rate breathing intensity and unpleasantness, and perform an inspiratory capacity maneuver. Cognitive assessments will be administered every 10 minutes. After the breathing task, participants will complete lung and respiratory muscle function tests.

Prior to Study Day 1 (the experimental visit), participants will be randomized to the order in which they are exposed to the interventional conditions (ambient/normal auditory feedback, enhanced auditory feedback, or removed auditory feedback with replacement of a self-selected music playlist). Upon arrival, an esophageal balloon will be placed to measure the pressure around the heart and lungs. Participants will then complete three full-length breathing tasks, in which they inspire against a predetermined resistive load for 60 minutes, with auditory conditions in the order of randomization. Biometric monitoring, cognitive tasks and participant ratings during the breathing tasks will be completed with the same frequency as Study Day 0. A 1-hour rest period will be observed between the breathing tasks.

Being tested
Ambient Noise, Increased Auditory Feedback, Noise Distraction
Keywords
Dyspnea Perception, Cognitive Performance, Auditory Distraction

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Ambient NoiseOther

    Participants will complete the breathing task with ambient (or normal) auditory feedback (~10 decibels).

  • Increased Auditory FeedbackOther

    Participants will complete the breathing task with increased auditory feedback of ventilation (~70 decibels). Specifically, a small microphone will be placed in the device that participants breathe through to increase the sound of the participants breath.

  • Noise DistractionOther

    Participants will complete the breathing task without auditory feedback of ventilation. Specifically, participants will wear noise cancelling headphones and will listen to a self-selected music playlist at a constant volume (~80 decibels).

Study groups in NCT07470099
Study groupRoleWhat they receive
Ambient noise, then music distraction, then increased ventilation auditory feedbackActive comparatorParticipants will complete 3 full length breathing tasks, one under each auditory condition. The order of condition exposure will be assigned via randomization.
Receives: Other: Ambient Noise; Other: Increased Auditory Feedback; Other: Noise Distraction
Ambient noise, then increased ventilation auditory feedback, then music distractionActive comparatorParticipants will complete 3 full length breathing tasks, one under each auditory condition. The order of condition exposure will be assigned via randomization.
Receives: Other: Ambient Noise; Other: Increased Auditory Feedback; Other: Noise Distraction
Music distraction, then ambient noise, then increased ventilation auditory feedbackActive comparatorParticipants will complete 3 full length breathing tasks, one under each auditory condition. The order of condition exposure will be assigned via randomization.
Receives: Other: Ambient Noise; Other: Increased Auditory Feedback; Other: Noise Distraction
Increased ventilation auditory feedback, then ambient noise, then music distractionActive comparatorParticipants will complete 3 full length breathing tasks, one under each auditory condition. The order of condition exposure will be assigned via randomization.
Receives: Other: Ambient Noise; Other: Increased Auditory Feedback; Other: Noise Distraction
Increased ventilation auditory feedback, then music distraction, then ambient noiseActive comparatorParticipants will complete 3 full length breathing tasks, one under each auditory condition. The order of condition exposure will be assigned via randomization.
Receives: Other: Ambient Noise; Other: Increased Auditory Feedback; Other: Noise Distraction
Music distraction, then increased ventilation auditory feedback, then ambient noiseActive comparatorParticipants will complete 3 full length breathing tasks, one under each auditory condition. The order of condition exposure will be assigned via randomization.
Receives: Other: Ambient Noise; Other: Increased Auditory Feedback; Other: Noise Distraction

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in Stroop Color-Word Test Time Performance

    Time performance on the Stroop Color-Word Test (min:sec) will be measured every 10 minutes during each breathing task.

    Measured: Before and after each Day 1 breathing task (approximately 60 minutes in duration)

  2. Change in Stroop Color-Word Test Error Performance

    The number of errors on the Stroop Color-Word Test will be measured will be measured every 10 minutes during each breathing task.

    Measured: Before and after each Day 1 breathing task (approximately 60 minutes in duration)

  3. Change in Perception of Dyspnea Intensity

    Participants will rate perception of dyspnea (breathing) intensity on a visual analog scale (VAS) every 5 minutes during each breathing task. The participant will draw a vertical marker line on a horizontal line (100mm), indicating their breathing perception from "not noticeable" (0mm) to "maximal imaginable intensity" (100mm).

    Measured: Before and after each Day 1 breathing task (approximately 60 minutes in duration)

  4. Change in Perception of Dyspnea Unpleasantness

    Participants will rate perception of dyspnea (breathing) unpleasantness on a visual analog scale (VAS) every 5 minutes during each breathing task. The participant will draw a vertical marker line on a horizontal line (100mm), indicating their breathing perception from "not unpleasant" (0mm) to "maximal imaginable unpleasantness" (100mm).

    Measured: Before and after each Day 1 breathing task (approximately 60 minutes in duration)

Secondary outcomes (8)
  1. Change in Diaphragm Thickness

    Diaphragm thickness will be measured via Doppler ultrasound of the 10th/11th rib space during functional residual capacity (FRC; rest) and end-inspiration, as well as during the maximal inspiratory pressure (MIP) test from FRC before and after each condition.

    Measured: Before and after each Day 1 breathing task (approximately 60 minutes in duration)

  2. Change in Heart Rate Variability

    Heart rate variability (beats per minute) will be measured continuously during each breathing task via 3-lead electrocardiograph (ECG).

    Measured: Before and after each Day 1 breathing task (approximately 60 minutes in duration)

  3. Change in Peripheral Oxygen Saturation

    Peripheral oxygen saturation will be measured continuously during each breathing task via pulse oximetry.

    Measured: Before and after each Day 1 breathing task (approximately 60 minutes in duration)

  4. Change in Blood Pressure - Brachial Artery

    Blood pressure will be measured every 10 minutes during each breathing task via a standard blood pressure cuff and auscultation of the brachial artery.

    Measured: Before and after each Day 1 breathing task (approximately 60 minutes in duration)

  5. Change in Blood Pressure - Finger Photoplethysmography

    Blood pressure will be measured continuously during each breathing task via finger photoplethysmography.

    Measured: Before and after each Day 1 breathing task (approximately 60 minutes in duration)

  6. Change in Heart Rate

    Heart Rate will be measured continuously during each breathing task by 3-lead electrocardiograph (ECG).

    Measured: Before and after each Day 1 breathing task (approximately 60 minutes in duration)

  7. Change in Cerebral Blood Oxygen Kinetics

    Oxyhemoglobin and deoxyhemoglobin (uptake/extraction, uM)will be measured continuously via near-infrared spectroscopy (NIRS) of the pre-frontal cortex during each breathing task.

    Measured: Before and after each Day 1 breathing task (approximately 60 minutes in duration)

  8. Change in Cerebral Blood Velocity

    Bilateral transcranial Doppler Ultrasound will be used to continuously measure middle and posterior cerebral artery blood velocity during each breathing task. The ultrasound transducers will be placed on both sides of the head at the temporal windows and the positions will be fixed using a transducer holder.

    Measured: Before and after each Day 1 breathing task (approximately 60 minutes in duration)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted13 Mar 2026
  2. Study start1 Jun 2027 (estimated)
  3. Primary completion1 Jun 2027 (estimated)
  4. Study completion30 Sep 2028 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Randomised
Intervention model
Crossover
Masking
None (open label)
Enrolment
15 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07470099
Sponsor's protocol ID
28381- Aim 2
Other IDs
FOAAFRLAFOSR20240007
Status last verified
Mar 2026
First submitted
10 Mar 2026
Last updated
13 Mar 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: The plan to share individual participant data (IPD) is still unknown. However, if other researchers request IPD, we will evaluate that request and determine to share IPD.

Questions about this trial

What is this clinical trial studying?

A study testing Ambient Noise, Increased Auditory Feedback and Noise Distraction in people with Work of Breathing, run by Indiana University at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 7 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 13 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Timothy D Mickleborough, PhD (812-855-0753, tmickleb@iu.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in Stroop Color-Word Test Time Performance (time frame: Before and after each Day 1 breathing task (approximately 60 minutes in duration)). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Mar 2026.

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