This happens to me when listening to a white noise app / machine that has a short loop. You can buy machines that are explicitly non-looping and it's so much better.
Most of these that I've encountered are webapps and they loop/crossfade a white noise sample rather than synthesize it. I don't think looping is the issue here though. I get the same voice-like auditory hallucinations even when playing with an analog white noise source in my analog synthesizers. A static square wave without any other sounds also causes them for me.
Most of these machines are 'multi-function' machines that play crickets / waterfalls, etc in addition to white noise. That sound is best handled by capturing a snippet and looping it over and over again. The same applies for white noise as well unfortunately.
Also it's usually a good idea to buy a little machine for this that uses like 5W vs running your computer all night.
It's crazy they loop, it just takes one transistor in avalanche mode to create white noise. Maybe I should mod my Bose Sleep buds that have ridiculously bad sound quality and short loops (and battery life).
It's easy electronically but if you're writing an app for a device/OS that doesn't implement that capability and expose it to apps you're left with either pseudorandom numbers or a sample. A very long losslessly compressed sample can be good but would require a large download, so in practice these apps generally have short, lossily compressed samples. These samples (and the alternative, pseudorandom numbers) sound absolutely awful. A human mind on the verge of sleep is an insanely powerful signal processing device and recogniser/producer/completer of patterns.
Raspberry Pis have hardware random number generators. I use one to generate smoothed brown noise for sleep. It's blissful.
I've been meaning to get round to solving this problem on phones, making an app that can, without a ridiculously large download, generate really high quality sleep noise. I have some ideas but it's not an easy problem.
> A human mind on the verge of sleep is an insanely powerful signal processing device and recogniser/producer/completer of patterns.
This resonates with my feelings. Hardware pseudo random noise is something i'd like to try, but I'm not sure my partner is so keen on it, how to deliver the sound in a discrete and non-intrusive way?
