You may have heard of ‘white noise’, particularly popular with helping babies sleep, but have you heard of brown noise?
In this blog, Dr Lindsay Browning, author of Navigating Sleeplessness, explains exactly what brown noise is, how it is different to white noise and also pink noise, why it is becoming popular and how it can help you sleep.
What is brown noise?
Brown noise is a specific type of sound which contains very low frequencies (the bass) at a greater volume and minimal higher frequency sounds. In nature, a natural example of this would be the sound of ocean waves hitting the shore, or the low roaring sound of the inside of an aircraft.
The low frequencies make brown noise, different to, for example, white noise.
Brown vs ‘other colour’ noise
White noise
White noise contains all frequencies of sounds at equal volumes, and the inclusion of high frequency sounds can make white noise unpleasant to listen to for some people. Examples of white noise would be the static from a television or radio.
Pink noise
Pink noise contains all the frequencies that white noise contains but with the higher frequency sounds at a much quieter volume, making the noise more pleasant to listen to. Examples of pink noise could be, in nature, the sound of steady rainfall.
There is interesting research to suggest that specific types of pink noise may be beneficial for memory consolidation, but this is extremely early research and we need a great deal more studies before any firm conclusions can be drawn.
Why is noise defined by colours?
The word white noise is used because all the frequencies of sound are included in this noise – just like white light has all the different frequencies (colours) of light included in it. Pink light includes a reduced number of the highest frequencies of sound and brown noise contains a greater focus on the lower frequencies of sound. The word “pink” and the word “brown” are supposed to signify the difference in focus of the sounds on the high and low frequencies.
What are the benefits of listening to brown noise?
The ‘use’ and discussion of brown noise has become increasingly popular – apparently #brownnoise has over 15.2 billion views.
Essentially, brown noise minimises external noise stimuli. It minimises distraction, giving your brain something monotonous to listen to and focus on.
If someone lives in a town or city where there is a lot of external noise, then sounds like traffic or sirens in the night can cause people to wake up from sleep – either briefly disrupting sleep quality or waking them up completely. Individuals can then struggle to go back to sleep.
Brown noise can help by masking the external sounds, making you less likely to be disrupted from sleep by the external noise.
How can brown noise help you sleep?
The use of a brown noise, white noise or similar for sleep can be helpful when you are sleeping somewhere quite noisy, such as with people talking outside or if you are in a hospital with beeping machinery. It can also be helpful for people with tinnitus to help to mask the unpleasant sound in their ears.
When we sleep, a part of our brain is also aware of the environment outside and responds to sounds. If these external sounds are sudden or loud, such as a barking dog in the night, that can cause us to wake from sleep. Brown noise can be used to mask such sounds, as discussed above.
Should you use brown, white or pink noise to help you sleep?
The scientific studies conducted so far have been conflicting as to whether listening to background noise during sleep is actually beneficial. A 2022 meta analysis of 34 studies where people used white and pink noise machines found no clear evidence that listening to these devices improved their sleep. However, they also did not find clear indication that they were harmful for sleep. Therefore, if you find listening to a noise machine helps you to sleep better there doesn’t seem to be a good reason for you not to do that.
However, if you are sleeping somewhere quiet that does not have loud external noises, then using brown noise could actually cause a degree of disruption to your sleep, rather than being wholly helpful. You are essentially adding noise, when it would otherwise be quiet.
Brown noise is also not recommended as the first line intervention for sleeping problems.
If someone is struggling with insomnia, then using brown noise is not addressing the issue, just potentially making a person reliant on a tool to help them sleep, which is not ideal. It may mean a person can then not sleep without brown noise. This is not a long-term solution. Instead, the recommended course of treatment is CBT-I which is cognitive behavioural therapy for insomnia.
Getting support with good sleep hygiene
If you are struggling to sleep and using brown or white noise to help, do consider if you are becoming reliant on its use to help you sleep regardless of the noise or disruptions in your sleeping environments.
It is important to improve your general sleep hygiene instead. Click below for good sleep hygiene guide.