Noise Exposure
Conditions
Keywords
Sleep, Cognitive Performance
Brief summary
Sound insulation of bedrooms is expensive and typically only granted to residents living close to the airport. We plan to investigate the effects of various aviation noises on sleep under controlled laboratory conditions and to investigate whether some of the sleep disturbing effects can be mitigated by introducing broadband noise into the bedroom or by wearing earplugs.
Detailed description
The Federal Aviation Administration is interested in investigating inexpensive yet effective methods to mitigate the adverse effects of aviation noise on sleep. The sleep of up to 28 subjects will be monitored with polysomnography and actigraphy over 7 consecutive nights in groups of 4 exposed to various sound conditions (aviation noise; broadband noise; aviation noise plus earplugs; aviation noise plus broadband noise at various decibel \[dB\] levels). Subjects will fill out surveys, perform cognitive tasks and a hearing test before and after each sleep period. The study will be performed in the Chronobiology Isolation Laboratory (CIL) in the Hospital of the University of Pennsylvania. This newly constructed facility includes 4 acoustically isolated bedrooms and a high-fidelity sound system. Eligible subjects are age 21-50, free of psychiatric conditions that preclude participation, and maintain a self-reported regular sleep schedule of 6-8.5 hours per night as verified by six days of ambulatory actigraphy and daily logs.
Interventions
OTHERAviation Noise Only (AN)
The aviation noise (AN) night will expose subjects to a pre-programmed recording of aviation noise and alerts during sleep from 2300-0700.
OTHERPink noise only, 50 dBA (BN50)
The BN50 night will consist of exposure to continuous pink noise throughout the sleep period at a level of 50 A-weighted decibels (dBA).
OTHERAviation Noise With Earplugs (AN+EP)
The AN + EP night will consist of the aviation noise (AN) exposure with the addition of wearing earplugs overnight.
OTHERAviation Noise With Pink Noise, 40 dBA (AN+BN40)
The AN + BN40 night will consist of the aviation noise (AN) exposure with the addition of continuous pink noise throughout the sleep period at a level of 40 dBA.
OTHERAviation Noise With Pink Noise, 50 dBA (AN+BN50)
The AN + BN50 night will consist of the aviation noise (AN) exposure with the addition of continuous pink noise throughout the sleep period at a level of 50 dBA.
Sponsors
Civil Aerospace Medical Institute
University of Pennsylvania
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Masking description
Subjects, study personnel and those assessing outcomes will be unaware of order of the exposure conditions. Investigators will only learn about the condition after the start of the sleep period of participants.
Intervention model description
We will investigate participants in 7 groups of 4 subjects each. For six nights following an adaptation night, a different noise condition occurred each night. Each participant of a group was exposed to the same condition in each study night. In this randomization paradigm, each condition will appear in each position exactly once, and will be preceded by each other condition exactly once.
Eligibility
Sex/Gender
ALL
Age
21 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Adult subjects between 21-50 years old * Free of psychological/psychiatric conditions that preclude participation. * BMI between 18.5 and 35. * Self-reported regular sleep schedule; able to maintain their sleep schedule during the course of the study. * Self-reported sleep duration of 6-8.5 h per night (verified by ambulatory sleep monitoring with wrist actigraphy and daily logs). * Ability to read/write English. * Fully vaccinated for or recovered from coronavirus (COVID-19).
Exclusion criteria
* Subjects habitually use broadband noise (e.g. white noise machines) to promote sleep at home. * Hearing loss greater than 25 dB in any frequency band up to 8 kilohertz (kHz). * History of neurological, psychiatric, or other medical condition that excludes participation. * Current mania or psychosis. * Current depression as determined by the Beck Depression Inventory with a score of 17 or greater (Beck, 1996). * Alcohol or drug abuse in the past year based upon history and urine toxicology screen. * Excessive alcohol intake (above 21 drinks per week) or binge alcohol consumption (5 or more drinks per day). * Excessive caffeine consumption (above 650mg/day combining all caffeinated drinks regularly absorbed during the day). * Current smoker/tobacco user, or using nicotine replacement therapy. Those that have been nicotine-free for 30 days will be included. * Body Mass Index at or below 18.5 or at or above 35. * Acute, chronic, or debilitating medical conditions, major Axis I psychiatric illness based on history, physical exam, blood and urine chemistries, and complete blood count (CBC). * Individuals who self-report a history of recurrent seizures or epilepsy or have a history of medical conditions that could increase the chance of seizures (e.g. stroke, aneurysm, brain surgery, structural brain lesion). * Cardiovascular, neurological, gastrointestinal, or musculoskeletal problems that exclude participation. * Major controlled or uncontrolled medical condition such as congestive heart failure, neuromuscular disease, renal failure, cancer, chronic obstructive pulmonary disease (COPD), respiratory failure or insufficiency, cardiac arrhythmia, or patients requiring oxygen therapy (as determined by self-report). * Currently working night, swing, split or rotating shift. * Current use or use of within the past month of a prescription or over-the-counter sleep medication or stimulant; use of psychoactive medication (based on self-report and review with a study clinician). * Pregnant or currently breast feeding. * Prior history or diagnosis of any sleep disorder including Obstructive Sleep Apnea (OSA) (AHI at or above 15 events/hour) from ambulatory or in lab polysomnography; Restless legs syndrome or periodic limb movement disorder; Insomnia; Parasomnia; High Risk of OSA based on Stop-Bang Questionnaire (yes on at least 4 of 8 questions); High Risk of Restless Legs Syndrome (RLS) based on Cambridge-Hopkins Screening questionnaire; High Risk of Insomnia based on Insomnia Severity Index (score of 22 or higher). * Individuals who self-report severe contact dermatitis or allergy to silicone, nickel or silver. * Planned travel across more than one time zone one month prior to and/or during the anticipated period of the study. * Intentional naps during the week. * Positive COVID-19 test at prescreening.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Time Spent in Slow Wave Sleep and Rapid Eye Movement (N3 + REM) | Days 2-7 | Combined time spent in sleep stages N3 and REM in minutes, as measured by polysomnography (PSG). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Cognition Efficiency | Days 2-7 | Efficiency scores from 10 brief cognitive tasks are generated from accuracy & speed of reaction/responding, represented here by standardized effect sizes, where higher scores indicate better performance. Test scores were adjusted for practice and stimulus set effects, and z-transformed based on average and standard deviation across all tests taken. Accuracy and speed across cognitive domains were calculated by averaging z-scores across the 10 tests, then averaged to calculate an efficiency metric. Scores between -0.2 and +0.2 suggest no effect on efficiency (0=population mean). Between -0.2 and -0.5 suggests a small negative effect (i.e. slightly less efficient). Between -0.5 and -0.8 suggests a moderate negative effect. Scores below -0.8 suggest a large negative effect. Between 0.2 and 0.5 suggests a small positive effect. Between 0.5 and 0.8 suggests a moderate positive effect. Scores above 0.8 suggest a large positive effect (i.e. significantly more efficient). |
| Cognition Speed | Days 2-7 | A single variable representing response time across 10 Cognitive tasks that cover a range of cognitive domains with known cerebral representation. Test scores were adjusted for practice and stimulus set effects, and z-transformed based on average and standard deviation across all tests taken. Speed across cognitive domains was calculated by averaging z-scores across the 10 tests. Higher scores reflect faster speed. Scores between -0.2 and +0.2 suggest no effect on speed (0=population mean). Between -0.2 and -0.5 suggests a small negative effect (i.e. slightly slower). Between -0.5 and -0.8 suggests a moderate negative effect. Scores below -0.8 suggest a large negative effect (i.e. significantly slower). Between 0.2 and 0.5 suggests a small positive effect (i.e. slightly faster). Between 0.5 and 0.8 suggests a moderate positive effect. Scores above 0.8 suggest a large positive effect (i.e. significantly faster). |
| Cognition Accuracy | Days 2-7 | A single variable representing response time across 10 Cognitive tasks that cover a range of cognitive domains with known cerebral representation. Test scores were adjusted for practice and stimulus set effects, and z-transformed based on average and standard deviation across all tests taken. Accuracy across cognitive domains was calculated by averaging z-scores across the 10 tests. Higher scores reflect better accuracy. Scores between -0.2 and +0.2 suggest no effect on accuracy (0=population mean). Between -0.2 and -0.5 suggests a small negative effect (i.e. slightly less accurate). Between -0.5 and -0.8 suggests a moderate negative effect. Scores below -0.8 suggest a large negative effect (i.e. significantly less accurate). Between 0.2 and 0.5 suggests a small positive effect (i.e. slightly more accurate). Between 0.5 and 0.8 suggests a moderate positive effect. Scores above 0.8 suggest a large positive effect (i.e. significantly more accurate). |
| Driving Simulator Standard Deviation of Lane Position | Days 2-7 | The standard deviation of lane position reflects the extent (in feet) to which participants swerve within the lane in a virtual driving simulator, often used to investigate the effects of impairment on driving performance, where higher values represent worse performance. |
Countries
United States
Participant flow
Pre-assignment details
The study was designed to expose all subjects to the six noise conditions after an adaptation night. However, the order in which subjects experienced each condition varied, resulting in seven different condition sequences. Subjects were assigned to a study group with up to 4 total participants, where each participant experienced the same condition sequence. A total of 27 subjects were enrolled and assigned to one of the seven sequences.
Participants by arm
| Arm | Count |
|---|---|
| Group 1: A B C D E F Subjects in Group 1 experienced the conditions in this order: A B C D E F. | 4 |
| Group 2: B D A F C E Subjects in Group 2 experienced the conditions in this order: B D A F C E. | 4 |
| Group 3: C A E B C D Subjects in Group 3 were scheduled to experience the conditions in this order: C A E B F D. However, the PSG system failed in three out of four subjects in study night 2. Therefore, it was decided by the PI to rerun the night 2 exposure (condition C) on night 6. In doing so, the condition originally planned for night 6 (condition F) was removed from this study sequence, and Group 3 subjects did not experience the condition F exposure. | 4 |
| Group 4: D F B E A C Subjects in Group 4 experienced the conditions in this order: D F B E A C. | 3 |
| Group 5: E C F B D A Subjects in Group 5 were scheduled to experience the conditions in this order: E C F A D B. However, due to an inadvertent selection of the audio sequence on night 5, the file for night 7 was played on night 5. Therefore, the noise conditions originally planned for night 5 and 7 were switched in order to expose subjects to all noise conditions. | 4 |
| Group 6: F E D C B A Subjects in Group 6 experienced the conditions in this order: F E D C B A. | 4 |
| Group 7: C D E A F B Subjects in Group 7 experienced the conditions in this order: C D E A F B. | 4 |
| Total | 27 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Withdrawal by Subject | 2 |
Baseline characteristics
| Characteristic | Group 1: A B C D E F | Total | Group 7: C D E A F B | Group 6: F E D C B A | Group 5: E C F B D A | Group 4: D F B E A C | Group 3: C A E B C D | Group 2: B D A F C E |
|---|---|---|---|---|---|---|---|---|
| Age, Continuous | 24.25 years STANDARD_DEVIATION 1.71 | 28.54 years STANDARD_DEVIATION 5.89 | 33 years STANDARD_DEVIATION 6.56 | 28.5 years STANDARD_DEVIATION 7.85 | 28.75 years STANDARD_DEVIATION 6.55 | 26 years STANDARD_DEVIATION 4.36 | 30 years STANDARD_DEVIATION 2.94 | 30 years STANDARD_DEVIATION 9.85 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants | 8 Participants | 1 Participants | 2 Participants | 2 Participants | 2 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 3 Participants | 1 Participants | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 1 Participants |
| Race (NIH/OMB) More than one race | 2 Participants | 8 Participants | 0 Participants | 0 Participants | 2 Participants | 0 Participants | 2 Participants | 2 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 1 Participants | 7 Participants | 2 Participants | 2 Participants | 0 Participants | 0 Participants | 1 Participants | 1 Participants |
| Region of Enrollment United States | 4 participants | 27 participants | 4 participants | 4 participants | 4 participants | 3 participants | 4 participants | 4 participants |
| Sex: Female, Male Female | 4 Participants | 19 Participants | 3 Participants | 2 Participants | 2 Participants | 2 Participants | 3 Participants | 3 Participants |
| Sex: Female, Male Male | 0 Participants | 8 Participants | 1 Participants | 2 Participants | 2 Participants | 1 Participants | 1 Participants | 1 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk | EG004 affected / at risk | EG005 affected / at risk | EG006 affected / at risk |
|---|---|---|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 4 | 0 / 4 | 0 / 4 | 0 / 3 | 0 / 4 | 0 / 4 | 0 / 4 |
| other Total, other adverse events | 0 / 4 | 0 / 4 | 0 / 4 | 0 / 3 | 0 / 4 | 0 / 4 | 0 / 4 |
| serious Total, serious adverse events | 0 / 4 | 0 / 4 | 0 / 4 | 0 / 3 | 0 / 4 | 0 / 4 | 0 / 4 |
Outcome results
Primary
Time Spent in Slow Wave Sleep and Rapid Eye Movement (N3 + REM)
Combined time spent in sleep stages N3 and REM in minutes, as measured by polysomnography (PSG).
Time frame: Days 2-7
| Arm | Measure | Value (LEAST_SQUARES_MEAN) |
|---|---|---|
| Aviation Noise Only | Time Spent in Slow Wave Sleep and Rapid Eye Movement (N3 + REM) | 188.5532184 Minutes |
| Pink Noise Only (50 dBA) | Time Spent in Slow Wave Sleep and Rapid Eye Movement (N3 + REM) | 195.9798771 Minutes |
| Aviation Noise With Earplugs | Time Spent in Slow Wave Sleep and Rapid Eye Movement (N3 + REM) | 209.51862074703 Minutes |
| Aviation Noise With Pink Noise, 40 dBA | Time Spent in Slow Wave Sleep and Rapid Eye Movement (N3 + REM) | 176.4599674 Minutes |
| Aviation Noise With Pink Noise, 50 dBA | Time Spent in Slow Wave Sleep and Rapid Eye Movement (N3 + REM) | 174.2895997 Minutes |
| Control | Time Spent in Slow Wave Sleep and Rapid Eye Movement (N3 + REM) | 219.0943443 Minutes |
Secondary
Cognition Accuracy
A single variable representing response time across 10 Cognitive tasks that cover a range of cognitive domains with known cerebral representation. Test scores were adjusted for practice and stimulus set effects, and z-transformed based on average and standard deviation across all tests taken. Accuracy across cognitive domains was calculated by averaging z-scores across the 10 tests. Higher scores reflect better accuracy. Scores between -0.2 and +0.2 suggest no effect on accuracy (0=population mean). Between -0.2 and -0.5 suggests a small negative effect (i.e. slightly less accurate). Between -0.5 and -0.8 suggests a moderate negative effect. Scores below -0.8 suggest a large negative effect (i.e. significantly less accurate). Between 0.2 and 0.5 suggests a small positive effect (i.e. slightly more accurate). Between 0.5 and 0.8 suggests a moderate positive effect. Scores above 0.8 suggest a large positive effect (i.e. significantly more accurate).
Time frame: Days 2-7
| Arm | Measure | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|
| Aviation Noise Only | Cognition Accuracy | 0.004818355 z-score | Standard Error 0.082094556 |
| Pink Noise Only (50 dBA) | Cognition Accuracy | -0.016730648 z-score | Standard Error 0.082952084 |
| Aviation Noise With Earplugs | Cognition Accuracy | 0.055614609 z-score | Standard Error 0.085599407 |
| Aviation Noise With Pink Noise, 40 dBA | Cognition Accuracy | 0.04713328 z-score | Standard Error 0.082902765 |
| Aviation Noise With Pink Noise, 50 dBA | Cognition Accuracy | 0.038223035 z-score | Standard Error 0.082087524 |
| Control | Cognition Accuracy | -0.035636712 z-score | Standard Error 0.080077528 |
Secondary
Cognition Efficiency
Efficiency scores from 10 brief cognitive tasks are generated from accuracy & speed of reaction/responding, represented here by standardized effect sizes, where higher scores indicate better performance. Test scores were adjusted for practice and stimulus set effects, and z-transformed based on average and standard deviation across all tests taken. Accuracy and speed across cognitive domains were calculated by averaging z-scores across the 10 tests, then averaged to calculate an efficiency metric. Scores between -0.2 and +0.2 suggest no effect on efficiency (0=population mean). Between -0.2 and -0.5 suggests a small negative effect (i.e. slightly less efficient). Between -0.5 and -0.8 suggests a moderate negative effect. Scores below -0.8 suggest a large negative effect. Between 0.2 and 0.5 suggests a small positive effect. Between 0.5 and 0.8 suggests a moderate positive effect. Scores above 0.8 suggest a large positive effect (i.e. significantly more efficient).
Time frame: Days 2-7
| Arm | Measure | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|
| Aviation Noise Only | Cognition Efficiency | -0.064223254075 Z-score | Standard Error 0.065476995 |
| Pink Noise Only (50 dBA) | Cognition Efficiency | -0.080820342 Z-score | Standard Error 0.065961006 |
| Aviation Noise With Earplugs | Cognition Efficiency | -0.002037537 Z-score | Standard Error 0.067457746 |
| Aviation Noise With Pink Noise, 40 dBA | Cognition Efficiency | -0.005021343 Z-score | Standard Error 0.065934126 |
| Aviation Noise With Pink Noise, 50 dBA | Cognition Efficiency | -0.02031753 Z-score | Standard Error 0.065473068 |
| Control | Cognition Efficiency | -0.061364516 Z-score | Standard Error 0.064361916 |
Secondary
Cognition Speed
A single variable representing response time across 10 Cognitive tasks that cover a range of cognitive domains with known cerebral representation. Test scores were adjusted for practice and stimulus set effects, and z-transformed based on average and standard deviation across all tests taken. Speed across cognitive domains was calculated by averaging z-scores across the 10 tests. Higher scores reflect faster speed. Scores between -0.2 and +0.2 suggest no effect on speed (0=population mean). Between -0.2 and -0.5 suggests a small negative effect (i.e. slightly slower). Between -0.5 and -0.8 suggests a moderate negative effect. Scores below -0.8 suggest a large negative effect (i.e. significantly slower). Between 0.2 and 0.5 suggests a small positive effect (i.e. slightly faster). Between 0.5 and 0.8 suggests a moderate positive effect. Scores above 0.8 suggest a large positive effect (i.e. significantly faster).
Time frame: Days 2-7
| Arm | Measure | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|
| Aviation Noise Only | Cognition Speed | -0.133247423 z-score | Standard Error 0.115983876 |
| Pink Noise Only (50 dBA) | Cognition Speed | -0.144315479 z-score | Standard Error 0.116338083 |
| Aviation Noise With Earplugs | Cognition Speed | -0.057069789 z-score | Standard Error 0.117437672 |
| Aviation Noise With Pink Noise, 40 dBA | Cognition Speed | -0.056543403 z-score | Standard Error 0.116319131 |
| Aviation Noise With Pink Noise, 50 dBA | Cognition Speed | -0.078872577 z-score | Standard Error 0.115981035 |
| Control | Cognition Speed | -0.08897121 z-score | Standard Error 0.115186663 |
Secondary
Driving Simulator Standard Deviation of Lane Position
The standard deviation of lane position reflects the extent (in feet) to which participants swerve within the lane in a virtual driving simulator, often used to investigate the effects of impairment on driving performance, where higher values represent worse performance.
Time frame: Days 2-7
| Arm | Measure | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|
| Aviation Noise Only | Driving Simulator Standard Deviation of Lane Position | 1.40658463 feet | Standard Deviation 0.088697515 |
| Pink Noise Only (50 dBA) | Driving Simulator Standard Deviation of Lane Position | 1.394516627 feet | Standard Deviation 0.08888539 |
| Aviation Noise With Earplugs | Driving Simulator Standard Deviation of Lane Position | 1.340740078 feet | Standard Deviation 0.089469215 |
| Aviation Noise With Pink Noise, 40 dBA | Driving Simulator Standard Deviation of Lane Position | 1.425292912 feet | Standard Deviation 0.088875405 |
| Aviation Noise With Pink Noise, 50 dBA | Driving Simulator Standard Deviation of Lane Position | 1.359432551 feet | Standard Deviation 0.088696012 |
| Control | Driving Simulator Standard Deviation of Lane Position | 1.377041493 feet | Standard Deviation 0.08827651 |