A neat trick...

I saw a nifty trick on Mastodon the other day. Someone pointed out that you can use the SoX library to generate sounds like you get from the bedside sleep aids. I'd forgotten SoX even has synthesizers, but it does. So you can use SoX to make ocean surf sounds. It's super simple, lag free, etc.

And best of all, I checked and discovered that SoX is available as a Termux package, which covers most android devices, so you can take this wherever you can go with an android device. A quick test shows it works just fine on my Samsung phone. Also seems to work on my Kindle Fire HD, but very very quietly, for some reason. Might have to poke at it more though.