In the U.S., over one-third of adults and children fall short on sleep. Sleep deprivation can increase a person’s risk for a variety of chronic ailments, including diabetes, obesity, and depression. For this reason, people are often looking for tools, like a white noise machine, to help them sleep better or fall asleep faster. We explore what white noise is, how it impacts sleep, and how to incorporate it into your nightly routine if you want to try listening to it.
What Is White Noise?
White noise refers to a noise that contains all frequencies across the spectrum of audible sound in equal measure. Because white noise spans multiple bands of sound, it is sometimes referred to as a broadband noise. Anecdotally, people often liken white noise to the static that comes from an untuned radio or television.
Researchers have studied the effect of white noise on humans for many years, finding evidence it can reduce crying in infants, improve work performance, and potentially help counteract symptoms of attention deficit hyperactivity disorder (ADHD). Multiple studies have also examined how white noise may affect human sleep.
White Noise vs. Pink Noise
Like white noise, pink noise is a broadband sound containing components from across the sound spectrum. Pink noise contains sounds within each octave, but the power of its frequencies decreases by three decibels with each higher octave. As a result, pink noise sounds lower pitched than white noise. Researchers have compared the sound of pink noise to the noise produced by a waterfall. Studies have found that pink noise can enhance deep sleep in older adults and improve cognitive performance.
White Noise vs. Brown Noise
Brown noise, often called red noise, is another broadband sound like white and pink noises. Similar to pink noise, brown noise contains sounds from every octave of the sound spectrum, but the power behind frequencies decreases with each octave. This decrease is twice as great as that in pink noise, resulting in a sound people perceive as deeper than either white or pink noise. In research trials, people have said brown noise reminds them of the sound of rainfall or a shower.
Studies have shown brown noise might be useful in reducing symptoms experienced by people who have ringing in their ears and at improving cognitive performance, but its effect on sleep has not been widely studied.
Does White Noise Help You Sleep?
A recent analysis of multiple studies looking at white noise’s effect on sleep has produced mixed results. The authors call into question the quality of existing evidence and conclude that further research is necessary in order to widely recommend white noise as a sleep aid. They also note that in some instances, white noise can disturb a person’s sleep and may affect their hearing.
Machines designed to promote sleep using the concept of white noise came about as early as the 17th century. Later, researchers conducted research on white noise and sleep throughout the 1970s, 1980s, and 1990s, finding that listening to white noise helped newborn babies fall asleep faster and affected the amount of time adults spent in different sleep stages when played throughout the night.
In a more recent study, adults fell asleep 38% faster while listening to white noise. Other recent studies have continued to find white noise positively affecting sleep. For example, people living in a high-noise area of New York City fell asleep faster and spent more of their time in bed asleep while listening to white noise. In another study, listening to white noise through headphones improved sleep quality for critically ill patients in a loud hospital unit in India.
More research is needed to confirm whether an inherent characteristic of white noise improves sleep — perhaps by synchronizing brain waves — or if the sound primarily helps by masking background noise.
Disruptive noise during sleep can cause changes in heart rate that suggest the sleeper is experiencing semi-awakenings. In a New York City survey, 64% of respondents said noise disturbed their sleep at least once a week. Globally, transportation sounds like cars and planes are considered a major contributor to poor sleep, with possible health ramifications. Researchers are hopeful that the steady hum of white noise might reduce a sleeper’s sensitivity to unpredictable noises from the environment.
How To Choose a White Noise Machine
There are many factors to consider when choosing a white noise machine:
- Machine or App: One of the first decisions to make when seeking out white noise is whether you would prefer a stand-alone white noise machine or a white noise app. A machine tends to be larger and more expensive, but it might come with better sound quality. A machine is a better choice if you prefer to sleep far from your phone. An app could be more convenient while traveling, since it does not require you to bring any additional devices with you.
- Cost: Consider your budget. Some white noise apps offer a free or very low-cost version. White noise machine prices vary greatly, with the lower-priced machines costing around $20 and the higher-end options costing more than $100.
- Sound Quality: Check reviews of the white noise products you are considering to see what other customers have said about the sound quality. White noise machines either play a digital white noise recording or mechanically create a white noise sound. Some people prefer one type of sound over another. If you opt for a digital recording, make sure the manufacturer says it has a clean loop, meaning it is not obvious when the recording ends and begins replaying.
- Volume Control: Being able to control the volume of your white noise machine is essential. Check the manufacturer’s specifications for the lowest and highest available volumes to ensure the white noise machine meets your needs.
- Sleep Timer: Most white noise machines have some type of sleep timer, but their functionality varies. Read the details about how the machines you are considering allow you to control the timer function. Some allow the user to program in any amount of time, while others have pre-set blocks of time you can choose from.
- Other Sounds: If you have never used white noise to help you sleep before, consider opting for a white noise machine or app that also has other sound options, in case you find you do not enjoy falling asleep to white noise. White noise machines and apps often offer other broadband sounds, like pink and brown noise, in addition to soothing nature soundscapes.
Setting Your White Noise Machine Volume
The National Institute for Occupational Safety and Health (NIOSH) guidelines state that exposure to noise measuring 85 decibels or more can become hazardous over time. Ringing in the ears and hearing loss are both risks of exposure to loud sounds.
One study found that nearly 65% of infant white noise machines and apps were capable of playing sounds louder than recommended when people slept very close to the device. When determining which volume setting to use for your white noise machine, consider downloading the NIOSH Sound Level Meter (SLM) App. This app allows you to measure the decibel level of a sound using your phone. If you are playing white noise from an app on your phone, you would need to use a second phone or digital device to test its volume level.
There are no official guidelines regarding the volume at which to set a white noise machine for sleep. In a study that obtained promising results, sleepers used a white noise machine set to a volume of 46 decibels. If 46 decibels does not feel like enough for you, gradually increase the volume, but be sure to stay below 85 decibels.
Tips for Incorporating White Noise Into Your Bedtime Routine
If you are interested in a white noise machine as a way to fall asleep faster, consider making it just one part of a healthy bedtime routine. Forming a regular health routine, including a bedtime routine, may provide positive health effects.
Try to begin getting ready for bed at the same time each night so you can maintain a consistent bedtime, even on weekends. Your bedtime routine may include engaging in personal hygiene practices like brushing and flossing your teeth, washing your face, or taking a warm bath.
Once you are in your bedroom, dim the lights, arrange your pillows, set your alarm for the next morning if necessary, then turn on your white noise machine just before turning off the lights. Consider whether you prefer the white noise to play all night long or only as you fall asleep, and set a timer as needed. Avoid screen-based devices during your nightly routine, and reserve your bed for nothing other than sleep or sex.
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