Most mornings I wake up feeling as though I have been trampled by a rhino. I rarely feel rested, despite having spent the previous seven hours unconscious.
I’ve been described as an ‘angry sleeper’ by my sister, who now refuses to share a hotel room with me because of all my night-time harrumphing and fidgeting. I have sleep props galore — a bite splint to stop tooth grinding, lavender pillow spray and a world-beating stack of eye masks. But so far, nothing has worked.
So when I heard about a science-backed way to get better deep, restorative sleep — the element that seems to elude me — I had to try it.
This latest weapon in the war on sleep disturbance is ‘pink noise’ — a cousin of white noise, but with more balanced, ear-friendly frequencies. It has been found by U.S. experts to improve the restorative phase of sleep called slow wave sleep, which accounts for 25 per cent of our shut-eye and makes us wake up feeling rested. Boosting slow wave sleep with pink noise has also been found to improve memory.
U.S. experts suggest pink noise can improve restorative phases of sleep and in turn improve memory
Thanks to technology, pink noise is not hard to come by, with a plethora of apps available. There’s even a soft toy called Ewan The Dream Sheep which plays pink noise ‘to lull your baby to sleep’, and apparently works on older babies too (even 49-year-old ones, I hope). First, I download a free app called Pink Noise and find that it sounds a bit like a tropical rain storm or a power shower.
The U.S. study, led by a professor of neurology on a group of over-60s, found that they performed three times better in a memory test after a night of pink noise than without and that the slow wave oscillations in their brain increased, meaning that their deep sleep was better quality. That’s potentially wonderful for all of us who worry that when we’re losing our keys we’re actually losing our marbles, as slow wave sleep is the phase that keeps us sharp and lays down strong memories.
‘Deep sleep is the most important part of sleep,’ explains independent sleep expert Dr Neil Stanley, former director of sleep research at the University of Surrey. ‘We need it for memory, forgetting, learning and growth. Everything that happens during the day, you keep in your memory, but during the night you sort out all that information.
‘Your brain is forgetting things you can usefully forget and laying down important things into your long-term memory.
‘If you practise a task until you are as good at it as you can be before bed, your brain rehearses overnight. You can be 17 per cent better at it by having slept well.’
But this particularly useful sleep tails off with age; in men from the age of 35, and women after 55. Boosting it in midlife could be a way to anti-age our memory.
Dr Stanley thinks pink noise could help me get the restorative sleep I’m seeking. He sets me two ‘before and after’ tests. I should be able to tell what difference it makes after three or four nights.
Dr Stanley says your brain can stay alert because of the ‘first night effect’ — the phenomenon where you are unable to relax in an unfamiliar room
To measure memory improvement, there’s a test where you cover 20 items on a tray with a tea towel and see how many you can remember in the space of a minute. I’m to do this twice a day before bed, and again when I wake up — without looking at the tray again.
To measure quality of sleep, I’m to fill out the Leeds Sleep Evaluation Questionnaire (LSEQ). This asks questions to rate how rested I feel in the morning. I’m to do this half an hour after waking from a normal night of sleep and again after using pink noise.
I enlist my nine-year-old son to find 20 items for the tray test and surprise myself by remembering 16. I set up the pink noise app on my phone, reach for my eye mask, my bite splint, pillow spray and sink into . . . irritation.
After 45 minutes I’m awake and acutely aware of my phone — have I put it on silent? Will it run out of charge? I switch it off and fall asleep, waking up at 4 am and dozing fitfully until 6.15. I score 12 on the memory test.
When I check in with Dr Stanley, he says it sounds as though I’ve had a case of the ‘first night effect’ — a phenomenon that many of us experience in hotel rooms, where we’re unfamiliar with the room, the bed, the noises, and can’t relax. ‘Until your brain can consolidate whether this is a threat or not, it will remain on alert.’
The next night, I sleep fine until 4 am when the cat starts howling at the dawn chorus. This is enough to set my mind whirring.
Pink noise isn’t enough to drown out an insistent cat or silence a racing mind. But, the next day, Dr Stanley tells me that I have probably managed to get most of my slow wave sleep, which kicks in after 20 minutes and lasts 60 to 80 minutes — and then again about two hours later. On learning this, I realise that Ewan The Dream Sheep will sadly have to go back to John Lewis, as it automatically turns off after 20 minutes.
My memory test shows no improvement on the night before.
So to round three. I throw the cat out and find a pair of SleepPhones: earphones embedded into a headband that deliver the pink noise directly to my ears. The next morning I score 18 on the memory test — almost a full house! My score on the LSEQ test also confirms that I feel more rested and alert.
After a week, I feel more rested than I have in years. I’m not bounding out of bed yet, but I’m infinitely more on the ball during the day. I’m definitely going to continue with my nightly noise — after all, who doesn’t want to remember where they put their keys?