Many adults struggle with sleep, with over 14 percent reporting difficulty falling asleep most days and approximately 30 percent experiencing insomnia symptoms, according to a 2020 CDC study. This nightly battle can be attributed to various factors including stress, health conditions, and uncomfortable sleep environments like city noise or a stuffy room. Sleep noises, characterized by their rhythmic and soothing qualities, are designed to assist in drifting off to sleep. As explained by Mary Halsey Maddox, MD, a sleep specialist and founder of Sleep Dreams, these noises primarily help by masking disruptive external sounds such as slamming doors, car horns, or sirens that might otherwise wake a sleeping individual.

When faced with an array of choices like white, brown, and pink noise, understanding their differences is key to finding the most effective aid for sleep. While white noise has demonstrated benefits in improving sleep quality in certain populations, including ICU patients, brown and pink noises have gained considerable traction, particularly on platforms like TikTok, where users praise their calming and snooze-inducing effects. Sleep experts, including Dr. Maddox, Chris Winter, MD (neurologist and sleep medicine specialist), and Raj Dasgupta, MD (physician and sleep expert), delve into these different noise types.

The realm of sleep sounds extends beyond the 'big three' (white, brown, and pink noise) to include purple noise, gray noise, and even black noise, which is essentially silence. Dr. Winter clarifies that each 'noise color' corresponds to a unique range of sound wavelengths. By adjusting specific wavelengths, like tuning an equalizer to static, different sound colors emerge. These soothing sounds—white, pink, and brown noise—are instrumental in relaxing the mind and body, effectively drowning out unwanted distractions. Consistent use of these sounds at night can also serve as a signal to the body that it's time to unwind, fostering healthy sleep hygiene over time.

White Noise: Often considered a saving grace for those living near loud environments or dealing with snoring partners, white noise plays all sound frequencies evenly. This creates a steady 'whoosh' or 'shhh' sound, which Dr. Dasgupta explains helps mask disruptive noises. Common examples of white noise include the hum of a refrigerator, an air conditioner, a hissing radiator, or a whirring fan. However, some individuals, including Dr. Maddox, find white noise to be somewhat loud and harsh, likening it to television static.

Brown Noise: Distinct from white noise, brown noise possesses a deeper, rumbling tone, entirely devoid of higher frequencies. Dr. Dasgupta describes its sound as reminiscent of distant thunder or crashing ocean waves, which many perceive as calming and grounding. Although scientific evidence specifically on brown noise’s sleep benefits is limited, anecdotal reports, especially from TikTok users with ADHD, suggest it can aid in focus and quieting the mind, with one user describing it as 'a weighted blanket for [her] brain.'

Pink Noise: Offering a gentler alternative, pink noise has a lower frequency than white noise, striking a balance between white noise and complete silence. Dr. Dasgupta notes its lack of sharpness in high pitches, making it sound like soft rain or wind—an ideal choice for those preferring a quieter background sound to facilitate sleep. Research, such as a 2017 study in Frontiers in Human Neuroscience, has even linked pink noise to improved memory and sleep quality, particularly in older adults. Both brown and pink noise are often favored over white noise due to their softer, more natural characteristics, mirroring sounds like ocean waves or rustling trees, which Dr. Dasgupta suggests can be more calming for long-term use.

Other Noise Types: Purple noise, contrary to brown noise, emphasizes higher frequencies and is generally not considered ideal for sleep, though it is sometimes used in tinnitus treatment, according to Dr. Winter. Gray noise, frequently employed in yoga and meditation, emphasizes both high and low frequencies with equal loudness, differing from white noise which has equal energy across frequencies.

Determining the 'best' type of sleep noise is not a one-size-fits-all endeavor, as Dr. Winter likens it to finding the perfect pair of pajamas. While research into the sleep benefits of various noise types is ongoing and expanding, Dr. Maddox emphasizes that 'there are no actual evidence-based studies at this time that suggest one sleep noise is better than the other.' Historically, white noise has been the preferred choice for quick sleep induction, effectively blocking annoying background sounds, as supported by a 2021 study in Sleep Medicine that found it lessens the effects of environmental noise on sleep quality in high-noise urban settings. For those trying white noise, Dr. Maddox advises maintaining a low decibel level to prevent potential long-term hearing issues.

Pink noise also enjoys popularity among sleepers and has been shown to boost slow-wave sleep, a crucial stage for feeling rested. A 2012 study in the Journal of Theoretical Biology indicated that some individuals sleep better with steady pink noise than with silence, as it calms brain activity and promotes more stable sleep. A 2022 review in the Journal of Clinical Sleep Medicine also suggested pink noise as a potentially helpful intervention for improving sleep outcomes, though Dr. Dasgupta notes that further research is needed to substantiate these findings. Ultimately, the choice comes down to personal preference. As Dr. Maddox advises, 'Every noise evokes different feelings in people, and right now, we don’t have enough evidence to suggest one is better than the other. I always tell patients to pick the noise that is the most calming to them!'

Several white noise machines are recommended to aid sleep:

• Yogasleep Rohm Portable White Noise Sound Machine: Endorsed by Dr. Winter for masking various disruptive sounds, this portable machine offers bright white noise, deep white noise, and gentle surf options.
• Hatch Restore 2 Sunrise Alarm Clock And Sound Machine: A favorite of WH love and life editor Lydia Wang, this device features multiple sound settings and an easy-to-use app for scheduling sleep and wake routines.
• SNOOZ Smart White Noise Machine: With 10 volume settings and an accompanying app, this machine is highly rated for its effectiveness.
• LectroFan White Noise Machine: Recommended by Dr. Dasgupta for its multiple settings, including 20 different fan sounds, this WH editor favorite is ideal for those unsure of their preferred sound 'color' and effective for blocking city noise.
• Adaptive Sound Technologies Sound+Sleep Special Edition White Noise Machine: Offering 64 non-looping unique sleep sounds, this machine is praised by reviewers for its ability to cancel out external noise.
• SNOOZ Travel White Noise Sound Machine: Compact and portable, the SNOOZ Go includes six settings (white noise, pink noise, fan noise) and a built-in Bluetooth speaker for daytime music streaming.