[rpozarickij]

I use the Background Sounds feature (in Accessibility settings) on iOS with a Bluetooth speaker every night while I sleep. It's quite battery-friendly and has several sound options alongside dedicated volume control with which you can set background sound volume independently of the main volume. It's also possible to add a shortcut button to this feature in the Control Center (the screen that's shown when you pull down from the top of the screen).

This makes occasional outside/neighbour noises much less noticeable, although I do keep earplugs near my bed just in case (not great for my tinnitus, but still usually better than without them if they're needed).