Broadband Sound and Sleep

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.