Sleep is a popular health news topic, as a large number of Americans suffer from at least occasional insomnia. Adding in that good sleep aids memory in older folks heightens the interest for any reader who’s worried about forgetting where their keys are again. The story describes some details of the study design and contains an audio file so readers can hear what the burst of pink noise sounds like.
Unfortunately, the headline exaggerates the study finding. Improving memory for one day in 13 adults doesn’t translate into improved sleep and memory for all older adults. In addition, the article takes a gee-whiz approach to the research presented. It’s not white noise, it’s pink noise! And it’s not just turning on an app or a pink noise generator, but precisely timing the pink noise to an individual’s slow-wave sleep pattern. As the complexity goes up, skeptical readers should be asking if the benefits are worth all the fuss. In the end, there’s not enough specifics about what the benefits are or what they might mean.
Poor sleep affects some 45% of Americans on any given week, according to the National Sleep Foundation. Fixes for sleep abound, including prescription and over-the-counter pills, continuous positive airway pressure (CPAP) machines for sleep apnea, better bedtime hygiene, and cognitive behavioral therapy. Moreover, sleep quality tends to worsen as folks age, and many researchers are exploring links between poor sleep and memory problems, including dementia. An intervention that helps elderly people sleep better and improves their cognitive abilities the next morning clearly would be a good thing.
The article makes clear that commercial development of a pink noise generator is in the future, so it’s too early to say what such a technology would cost. Indeed, we’re told that the researchers hope to develop an affordable device. Affordable is too vague to be helpful here. We encourage reporters to at least dig up some numbers on existing alternatives. For instance, there are 99-cent apps to generate white noise and presumably higher quality speaker devices that run up to $120. But the pink noise study relied on timing the noise to sleep waves — so would a commercial product need to include an electroencephalogram device as well? That seems a different price category altogether.
The story tells us slow wave oscillations increase, but not by how much, or whether the increase is significant. The article is lacking important details around the intervention such as what an increase of slow wave oscillations might mean, say to a sleep wave expert or to an individual with sleep problems. Readers also learn that in a memory test taken in the morning, participants did three times better. But there are no details on what the memory test is or even what the “three times better” is compared to. (To the memory test the evening before? Or to the morning memory test after the no pink noise night?)
The absolute number (exact number of patients seeing a measured benefit) would be preferable to the relative number (“performed three times better”), particularly in a small study like this one, with only 13 participants.
In addition, there’s no discussion of how a memory test after sleeping can relate to long-term term memory effects. Improving memory for one day is not likely to be meaningful clinically.
The article does not mention harms at all. There may be no real harm to hearing these sounds as one sleeps, but we’d like to see that question addressed.
The article makes clear it’s a small study and the study author says that bigger and longer term studies are necessary. That’s good, but we’d like to see readers warned a bit more explicitly that these data are not nearly enough to make any kind of conclusion. And the story’s headline claims — unequivocally — that pink noise does indeed improve sleep and memory, which is an overreach.
The outcome (a “memory” test) really doesn’t seem like a rigorous outcome and certainly not one that can be extrapolated to long-term memory effects.
Good sleep is important for a number of health outcomes. It’s also pretty easy to make less-than-perfect sleep — a certain number of hours of uninterrupted sleep — sound terrible. This article does not engage in any of that kind of disease mongering.
The only source quoted in the article is a study author. The article states that one of the study authors (it’s not clear whether it’s the one quoted or not) has co-founded a company to develop a commercial device.
We applaud the story for including this conflict of interest but we’d like to see at least one source not involved in the study for an unbiased perspective.
The article does mention some other soothing sounds that might help people sleep better, such as music, nature sounds, or white noise apps. It would have been helpful to include some other strategies for improved sleep as well such as over-the-counter sleep aids, sleep hygiene (exercise, limiting naps, restricting certain foods before bedtime), and cognitive behavioral therapy.
The article makes clear that a pink noise generator timed to slow wave sleep is not yet available. The article does mention (parenthetically) that pink noise apps exist.
The writer addresses previous work by this researcher, which shows improvement in sleep and memory measure in young adults. The current study is new in that it tested the intervention in older adults. It’s not clear how much research has been done on pink noise and its effect on sleep and memory. We did find a study published in the journal Neuron in 2013 suggesting that pink noise helped participants achieve deeper sleep.
The article does not seem to rely solely on a news release, but not including independent sources is a shortcoming which is addressed under the Independent Sources & Conflicts of Interest criteria.