The research into pink noise and sleep has been pioneered by Phyllis Zee at the Northwestern University Feinberg School of Medicine. Her research is useful because it confirms what we, here at Soundmask, have always known anecdotally: sound masking can be great for sleep. (Especially when it’s masking a disturbing noise that’s preventing you from sleeping!)
For the purposes of research, I have a commercial Soundmask system installed in my home. It has saved me countless hours of sleep that would’ve been lost due to roadworks and loud neighbours. Not to mention noisy family members.
But enough of the anecdata. Did you know that there’s all sorts of research being undertaken about sounds and sleep? And products coming onto the market without much research at all. Seems everyone is jumping aboard!
White noise for babies
Many parents invest in a white noise machine for their infants. This is said to be soothing, like the sounds of the interior of the womb. The main risk of this kind of device arises when the speaker is not sound-limited.
Pediatrics journal found that hearing loss occurred in infants due to white noise machines, and a more recent study came to the same conclusion. But only when parents turned the volume up above 85dBA! I mean, come on, guys! That’s the noise level of a dog barking.
Even if the sound levels are set low, it’s worth remembering that white noise is really annoying. Fortunately, it’s not the only colour of noise.
#pinknoise trending
Tik-tok has been trending with noise for sleep. Apparently, the hashtags #brownnoise and #pinknoise have racked up over 175 million posts. This is in part driven by Zee’s research, which found that specifically-timed sound can improve sleep and memory in older people with mild cognitive impairment. You won’t find many articles adding all of that italicised context, though. Which probably explains why the Gen Zs are leaping onto the trend.
Naturally, there is an industry growing out of these kinds of findings.
AI-powered soundscapes
Amazon has backed Endel, a business that has developed AI-powered “soundscapes” to be used in the Alexa product. Endel focuses on:
creating personal artificial intelligence-powered soundscapes that take into account an individual’s immediate conditions. It does this by assessing a person’s current state and generating an appropriate soundscape from components of its sound engine. This process was born out of scientific principles about sound’s effect on the human body and mind.
Whether you’d want to be beholden to artificial intelligence for your sleep is a personal choice. But from our own experience, using microphones in a space runs the risk of compromising privacy.
Either way, the research behind the concept is interesting, as described by one of the co-founders, Dimitry Egrafov:
Listeners may also notice that the AI-powered soundscapes are often very simple. Using less complex tones, melodies, and movement helps ease the burden on our minds. We started with simple ratios of two tonal frequencies like octaves, 2:1, or a perfect fifth, 3:2, because those are pleasing to the brain. A new model suggests music is found to be pleasing when it triggers a rhythmically consistent pattern in certain auditory neurons.
Natural sounds
Back in the non-technical wheelhouse are regular old natural sounds like recorded rainfall, waves, and so on. Or even, if you’re in the right climate, actual waves and rain.
There is a lot to be said for the peaceful sounds of nature. Even science agrees, with studies like this one from the University of Sussex confirming what we all kind of intuitively knew already:
The lead author, Dr Cassandra Gould van Praag said, “We are all familiar with the feeling of relaxation and ‘switching-off’ which comes from a walk in the countryside, and now we have evidence from the brain and the body which helps us understand this effect. This has been an exciting collaboration between artists and scientists, and it has produced results which may have a real-world impact, particularly for people who are experiencing high levels of stress.”
So there you have it, folks. A small taste of how sound can work to aid sleep and cognition throughout all stages of life. But it’s likely free pink noise apps will remain the preferred noise of choice for some time.