Would like to second ear plugs, it took some testing to find the right softness/size because I have very small ear canals, but these slim-fit earplugs have been life-changing for my sleep: https://a.co/d/38Kftbm

The earplugs don't completely cut out environmental noise, but they dampen it enough that I don't find myself being awakened by any bumps in the night.

And snipping down the tail ends of the earplugs with scissors helps reduce pressure if you're a side sleeper.