Is it possible to train yourself to fall asleep in loud environments?

For example, if someone is sensitive to sound (unable to fall asleep if someone in the next room is talking) can they become less sensitive to sound?
I could wear earplugs, but I do not find them comfortable.
A similar question; is it possible to train yourself to not wake up so easily when sound does occur? For example if I were to be sleeping, and a garbage truck comes through the street to pick up trash, causes noise which could wake me up. Would it be possible that I train my brain to not wake up during such an event?

I don't know if this helps, but did you ever wonder how can people in Las Vegas sleep? The fact is that they can easily sleep with all the noises, but if you put them into a country town, with some crickets (is this the word?) they will have a hard time falling asleep due the "sounds".

It's because your brain ignores loads of signals/sensations and only notices what it considers to be important/relevant. Although I doubt that you can ignore any loud noises if they happen spontaneously (unless you're really in deep sleep), you can still get used to common sounds (like background sound). How long it takes to get used, I don't know. A good example that these changes happen is when you get a new fridge that makes a freaking high noise. After one week you seem to barely notice it.

Sleep with a fan. If you sleep in silence, even the sound of a pin dropping in the other room could bother you.