No idea if it works for you, but if I need to sleep _really_ well I wear ear plugs, even in a relatively quiet room. They need to fit right (rolled between your palms to squish them up, then they should barely fit inside your ear and expand to fill gaps).

The first time I did this it was revelatory. I woke up feeling like a new person. Sadly I don't much these days, because sleeping through a hungry/wet/scared infant isn't as acceptable (also I was a little disturbed what I could, in fact, sleep through, and whether that included smoke alarms)