White noise is the first thing we hear when
we're born, with the sounds of the outside world filtered through our mother's
body while we're in utero. White noise is also what you hear in a seashell,
which also acts as a filter by eliminating certain frequencies and amplifying
ambient noise through resonance. It turns out that silence is pretty much a
myth and noise is all around us. Perhaps the best way ahead is to choose our
personal level of exposure by listening to music or turning on a white noise
app before we go to sleep.
While it might seem counter-intuitive,
listening to noise can be incredibly relaxing. White noise has already helped
millions of insomniacs to fall asleep, with a single constant low level noise
source able to filter out abrasive and distracting noises from the environment.
In order to understand how white noise can be so powerful, it's important to
understand sleep and relaxation from an evolutionary perspective.
According to Rafael Pelayo, a clinical
professor of psychiatry and behavioural sciences at the Stanford Centre for
Sleep Sciences and Medicine, our bodies still believe that sleep is inherently
dangerous. Whether it's a physical threat, a baby screaming, or someone trying
to steal our stuff, people have evolved to wake up quickly when they hear a
surprising noise. In the modern urban world, however, this noise is more likely
to be a rubbish truck, an overhead plane, or a drunk person stumbling down the
“The thalamus needs to decide if a noise is
worth informing the cortex. There’s a concept in sleep called the arousal
threshold – it’s the stimulus you need to go from a deep sleep to awake."
said Pelayo, adding "The idea of a noise generator is to raise the
background noise so you don’t notice the sounds that aren’t worth your
attention: a snoring partner or the hotel elevator.”
While we'd all like to fall asleep next to
the ocean, it turns out that everyone can benefit from white noise with little
more than a smartphone on their bedside table. In fact, noise apps give us a
much greater degree of control over the level and type of noise, with people
able to choose between ocean noise, a waterfall, a distant crowded room, or
even an air conditioning unit. As the world around us gets noisier and harder
to control, a simple white noise app on your smartphone may be the secret to a
good night's sleep.
Image source: luca