Does white noise really help you sleep better?
White noise is called the sound similar to that emitted by a television when it does not tune in to any signal and that helps to cover or mask the others
White noise is known as a type of sound that brings together all the frequencies that the human ear is capable of capturing, all of them with the same amplitude and power. It is called this in reference to what happens with light: white light is the sum of all colors. White noise would also be, in some way, the sum of all noises.
What does white noise sound like? Well, like the static from the radio or television when they don’t tune in any signal. Or like an air conditioner turned on. Or like the homogeneous and constant hum that we hear when traveling by plane. Or like the one generated by washing machines, hair dryers, fans, and some other electrical appliances.
The fact is that there has long been a belief that white noise can help you sleep better, in the same way, that it is claimed to be beneficial for calming babies and young children.
For this reason, there are many applications for phones and tablets that play this kind of sound, and also many videos with the same effect on YouTube and other platforms. Specific devices are also sold to generate white noise. But how much truth is there in all this?
Positive effects of white noise
Until a few years ago there were not too many scientific studies on this issue, although there were some. In 2005, researchers in the United States analyzed the effect of white noise on the quality of sleep of patients admitted to the intensive care unit (ICU) of a hospital.
The work came to the conclusion that white noise reduced the number of times the patients’ sleep was interrupted since it found that the main cause of these awakenings was not the volume but the sudden variations of the sound: the sudden change from soft to strong.
What white noise does, the study’s conclusions explained is “reduces the difference between the noise floor and the noise peak.” Consequently, it increases the tolerance thresholds for occasional noises that frequently occur in an ICU room.
Scientists from Iran reached similar results, in a study published in 2016. They observed that after just three nights of hospitalization, the hours of sleep of patients in the coronary unit were reduced from more than seven to less than five. In addition, the time needed to fall asleep doubled: it went from 12.6 to 25.8 minutes.
Therefore, they decided to try white noise. What happened? The patients who slept accompanied by that sound, also after three nights in the hospital, did not show significant changes in the number of hours of sleep or in the time it took to fall asleep.
The conclusion of the Iranian researchers was to recommend the use of white noise “as a method to mask environmental noises ” and thus “improve the quality of sleep and avoid its interruptions” in the coronary care unit. What Is White Noise?
Higher subjective and objective quality of sleep
The most recent workers left the hospital units to see what was happening in other places. One of them, carried out in Indonesia and published in April this year, analyzed the sleep of twenty students – women between 16 and 18 years old – in a shared dormitory.
The test participants slept for thirty consecutive nights accompanied by white noise, which played non-stop between 10 p.m. and 5 a.m. the next morning. They then completed the Pittsburgh Sleep Quality Index ( PSQI ), a questionnaire to measure subjective sleep quality.
The results were positive: in the shared bedroom – a space in which, as there are so many people, various noises tend to be produced and, consequently, difficulties to sleep well – white noise made the quality of sleep better.
And another recent study (published in July of this year) focused on ten people living in New York City who had difficulty sleeping due to the noisy environment. This noise pollution is a feature of almost all large cities: noise is the second most harmful environmental stressor in Europe.
In this case, the researchers evaluated the subjective quality of sleep (through another questionnaire, called the Consensus Sleep Diary ) and also its objective quality by means of an actigraph, a device that looks like a wristwatch and allows analysis of duration and sleep patterns.
Both parameters showed “significant improvements” when sleeping with white noise. For this reason, the authors of the study point out that “the application of white noise can be an effective tool to help improve sleep” in environments with noise pollution such as large metropolitan areas.
Possible risks of always sleeping with white noise
Beyond the fact that all these studies point out the benefits of white noise for sleeping – and even the National Sleep Foundation, in the United States, highlights its advantages – there are also specialists who warn about possible counterproductive effects of accompanying sleep with this sound.
They emphasize, on the one hand, that there is no general rule that works for everyone: the most suitable environmental parameters for sleeping—sounds, lighting, and temperature— vary depending on each person.
On the other hand, always sleeping like this could generate a kind of conditioned reflex, something like an “addiction” to white noise. This could make it very difficult for that person to sleep without white noise in the future, which can be a problem if he has to sleep somewhere else, with a future partner, etc.
And also, although we have reviewed several studies here, the scientific evidence is still limited and in general the tests and experiments have been carried out with few people. Therefore, it is still too early to take the suitability of this resource for granted.
In any case, complete silence still seems to be the most suitable environment to achieve quality sleep. But white noise and the way it absorbs or masks disturbing noise could be a possible solution for those who live in an environment that is too noisy, such as big cities, and especially in their busiest areas. neo graft