There’s sound dampening as a route. Have you tried ear plugs? It won’t block all frequencies, but might be a low investment, high return area. Or adding background noise? I’ve used brown noise before and it seemed to help. No idea how to help with the low frequencies though. At least, not that wouldn’t make your apartment/flat a problem to those around it.
Sleep is a fundamental need for everyone. For me, it’s migraines that I could say I need to focus on sleep to ameliorate. For you, it’s “the spectrum”. It’s really just being a living being that makes sleep fundamental.
I'm a very light sleeper. The two biggest things that wake me are movement and noise. After recognizing those, tackling those two issues over the last few years has made an enormous positive impact on my mood, productivity, and overall quality of life.
Not going to detail my life's story here but if you live/sleep with a partner who tosses and turns all night and believe that their movement and getting out of bed is bothering you, run an experiment and sleep in a separate bed for a week. If your sleep quality improves, consider upgrading your bed to separate memory foam mattresses, or have a spare bed you can crash in for nights when you REALLY need to sleep. If your SO loves you, they will understand.
White noise. We used to run a box fan all night just for the noise but it turns out that those things use a tremendous amount of electricity. We switched to white noise machines which generate pretty much the same sound but use almost no electricity in comparison. The white noise machines are better than a smartphone because they have bigger speakers that can generate the mid-to-low range noise that phones cannot. Years ago we bought the "Lectrofan" machines on Amazon but those are now crazy expensive. (We paid like $15 back in the day, now they are $43-$50.) Your average HNer could probably rig up something just as effective with an old ipod and set of computer desktop speakers for free.
Earplugs, if you can stand them. I like the Howard Leight MAX earplugs. I buy them in bulk and stash them everywhere around the house, garage, and in my car. For sleeping, I reuse one pair for up to a week.
tried, waxes out my ears and more so - don't work against low frequencies due to wavelength and being hyper sensitive, I kinda feel it a bit more than most.
As another commentator mentioned - Deep Sleep and more so a build up of disturbances of that, stack the issue. Things like stress build up then as well, so all a vicious spiral sometimes as stress don't help at all.
But it's getting better and working on a move to some place more suitable as well as making best of what I can and identify, dampen/block best I can.
My custom made earplugs block less noise than the ones stuffed into the ears. And my understanding is that is to be expected.
I plan to have another pair of customs made and possibly see if I can get some custom ones for AirPod Pro tips. Running in the third world can be a kind of hell with the honking, construction, and fireworks.
Sleep is a fundamental need for everyone. For me, it’s migraines that I could say I need to focus on sleep to ameliorate. For you, it’s “the spectrum”. It’s really just being a living being that makes sleep fundamental.