If you find it difficult to switch off after a long day of staring at screens and drinking way too much caffeine, ‘pink noise’ might be the secret to finally getting a good night's sleep.
The soporific effect of white noise (a combination of many different frequencies of sound, all playing at the same time) has been known for a while: people who suffer from sleep disorders and sleep-deprived parents often use it as a bedtime aid to better help them or their young children to drift off.
What’s less widely known, however, is that white isn’t the only sonic ‘colour,’ as noise can be pink, brown, blue, violet and grey: there is a whole spectrum of noise, classified according to their frequencies.
A new study published in Frontiers In Human Neuroscience suggests that so-called ‘pink’ noise might be even more conducive to nodding off than white noise. Pink noise has a consistent frequency, with the power per hertz decreasing as the frequency increases. What does this mean for you? It sounds more natural than white noise, and so is arguably more relaxing. As Dr. Phyllis Zee of Northwestern University explained to Time, ‘the noise is fairly pleasant; it kind of resembles a rush of water. It’s just noticeable enough that the brain realises it’s there, but not enough to disturb sleep.’
The sleep of 13 adults with an average age of around 75 years was monitored over two nights: on one of these nights, the participants listened to pink noise as they went to sleep. Not only did the pink noise result in deeper sleep, it also helped them better complete a memory test: participants performed three times better than when they had fallen asleep without the noise.
For Zee, the positive benefits of pink noise are down to the way the sounds match up with the slow wave oscillations of deep sleep. ‘The effect here, at least for memory, is quite related to the ability of the sound stimulus to enhance slow-wave sleep,’ she explains.
If you’re keen to test out pink noise for yourself, head to YouTube: you’ll find hours of sound that you can queue up for the night. Sweet dreams…