Comment by anigbrowl | Hacker News Reader

Comment by anigbrowl | Hacker News Reader

Researchers observed 25 healthy adults, ages 21 to 41, in a sleep laboratory during eight-hour sleep opportunities over seven consecutive nights.

Absurdly low n. Additionally, I've become very skeptical of anything coming out of sleep labs after my wife was sent to one (at a prestigious teaching hospital) by her doctor some years ago: the 'sleep opportunity' was lights out at 9pm for 8 hours, and the staff were wholly indifferent to the fact that she's a night owl and prefers to sleep after midnight. Additionally she reported that it was not particularly quiet or dark.

I am not a fan of noise machines but I have noticed that I sleep best on rainy nights, which has a similar average sound spectrum, and is about the same as the sound of your blood circulating near your eardrums. Testing pink noise along with aircraft noise (which is closer to red noise) is equivalent to just making the noise level higher with slightly more midrange energy. Some noise can be relaxing for light sleepers; too much is just annoying.

The thing that stood out more to me than the n being low is "the participants reported not previously using noise to help them sleep or having any sleep disorders." Sleeping with pink noise seems like something that you'd end up getting acclimated to.

My n=1 is that I often sleep with a fan on and live in NYC -- whenever I stay in a place where there is no noise I tend to have trouble sleeping, so I end up turning on some nature sounds on my phone from myNoise.

Yeah that seems silly. I was a quiet-room sleeper until I met my wife, who needs some kind of white noise to sleep. I eventually adapted and now sleep much better with noise than without (at least subjectively), but that change took a while, at least several months. I found it quite difficult to sleep with for a while.

I slept without noise for years until I needed it for a while for (reason) and now it feels difficult to sleep without noise. Acclimation’s a real effect

Confounding variable: the presence of your wife may be aiding your sleep more than the noise.

That is a low n, but I’m not sure what the alternative is. Surely random anecdotes (n=1) are even less powerful?

Random anecdotes might be less biased. For example, no pressure to publish nor sell a product.

The low n is not the only questionable thing about the study. What a big n gives you is diversity of samples and tighter confidence intervals, but it can not correct for methodological limitations. Specifically, they didn't invite any people with sleep issues or who are already sleeping under noise. Therefore the conclusion is a "duh" - if you don't require pink noise to sleep, then don't add it.

I'm not inviting you to draw conclusions from my semi-random (but informed by years of professional thought about why people like different sounds) anecdote.

Personally, I trust the results of a sleep study, or any study on anything, by people I don’t know with questionable incentives than I do anecdotes of commenters I’ve been following for 10 years on HN, especially when they align with my own experiences, and conversations I’ve had over beers with people in industry (whatever that might be).

A lot of “science” is junk, not insofar as it’s false, but like water is wet.

Good science: there are compounds in cruciferous vegetables that appear to exert some health benefits.

Junk science: bok choy is green.

If a sleep lab is ignoring the fact of chronotypes (it’s obvious our genetic history would require some people to be predisposed to keep an eye out for toothy clawed things, and dangerous ‘others’) while most of their tribe / community are sleeping), the people who work there do so because it pays the bills, not because they’re passionate about working in the medicine / health industry at all.

I encourage people to get up and walk out if you find yourself at a service provider that doesn’t care about you. Find someone who gives a frak.

Once again, I am not suggesting you generalize from my anecdote. I like the sound of rain and sleep better with it. I have absolutely no idea how widespread this is in the population.

The alternative is higher n. The study makes a claim, it does not present the evidence necessary to back up that claim. Until someone does a larger study, no conclusion should be drawn.

Perhaps too meta or off topic but I thought it was funny that you thought their n was low and then cited a story about one person.

The way I’m understanding it is that it’s more that if there’s a real population of people like his wife, that is only 5 percent of the actual population or even higher, for example, it may not be caught by such a small sample size.

But that is true of all sample sizes

I’ll match your anecdote. I slept with white noise in my former home which was in a noisier town and felt it improved my sleep. Now that we’ve moved to a nice historic neighborhood I find I sleep best with nothing on at all. The silence there is so wonderful. Maybe silence is the ultimate luxury.

My options are "fairly loud, low rumbly, mostly full spectrum noise" or "continual, nonstop barking." Only one of these options makes sleep possible. :) I'd prefer quiet, but it's so rare to actually have it.

It's a within-subject design and they literally did a power analysis in the paper. This is not absurdly low n.

>Absurdly low n

Please divulge the statistical calculus showing this is an absurdly low n. Please explain how to determine the appropriate sample size.

No, "number _seems_ small" is not adequate statistical reasoning.

Sleep studies often have low numbers of participants because conducting tests in a controlled environment of a sleep lab is expensive and time consuming, as they have only so many beds.

I wonder if gentle noise might be relaxing in the same way that watching trees swaying in the wind is relaxing.

Common sense and experience inform my theory of good sleep: Pitch black, stone quiet, with noise limited to pre-sleep audial approximations of the dream-like mental noise that precipitates sleep.

Glad that works for you! To me, silence sounds a lot like insomnia.

> -sleep audial approximations of the dream-like mental noise that precipitates sleep.

What does this mean for you?

My hypnagogia, or mental-noise that precipitates sleep as you put it, is entirely visual hallucinations.

I’m not aware of ever having been able to recall any auditory hallucinations.

Sleep labs are like doctors are like mechanics are like restaurants - their only legal obligation is to not kill you,

not be of any particular quality.

Do your homework.

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