If you – or your partner or child – has ever had trouble sleeping, you’ve probably heard of ‘white noise’. It’s a common solution to sleep woes, especially in noisy environments. Here’s a look into how it works – and more importantly, how you can put it to work for you.
What exactly is white noise?
In the most technical terms, white noise is a unique pattern of sound which is used to mask background sounds. Audiologists would describe it as ‘noise with a constant amplitude throughout the audible frequency range’.
This kind of ‘pure’ white noise can only be generated electronically using precise mathematics. It sounds a lot like radio static, with a harsh, high frequency energy. Interestingly, there are many other ‘colours’ of noise – red, brown, violet, grey and pink – each with different technical applications in acoustics and engineering.
But less technically, the term ‘white noise’ is often used to describe any kind of constant, unchanging background noise – anything from nature sounds such as waves, a crackling campfire or the buzz of cicadas, to the artificial hum of an air conditioner or vacuum cleaner.
So why should you care about it?
If you’ve ever struggled to sleep through the sound of a noisy neighbour or barking dog, white noise could help you.
According to some neuroscientists, our hearing evolved as a biological alarm system, and it never switches off. As we sleep, our brain is constantly monitoring the input from our ears – a bit like a cognitive night watchman – and anything that seems unusual will alert us that something’s wrong.
In this way, it’s not the volume of the sound that startles us, it’s the context. A recent study in hospital intensive care units showed that what really disturbs sleepers is not the magnitude of ‘peak noise’ itself but the difference between this peak noise and the background noise.
In practise, this means that by adding white noise to your sleeping environment, you mask the sound of the unusual noises that would otherwise normally wake you – and continue snoozing, blissfully unaware.
How do you use it?
These days, white noise comes in many forms you can use at home.
If you’re flush with cash (and, presumably, very short on sleep) you can purchase a cutting edge ‘sleep sound system’ for hundreds of dollars. But easily available smartphone apps and MP3s do a similar job.
Or if you’re really desperate, and it’s the middle of the night with a thumping soundtrack coming from next door – just switch on a desk fan or do a load of washing. It might not be perfect white noise, but it may just be enough to get you through till morning.
This post originally appeared on the National Hearing Care blog and forms part of a series exploring the relationship between sound and sleep.