I understand if clinical staff are actually coming to check on you. In many cases you may need to be checked on every few hours to prevent some decline in condition from going unnoticed. What I don't get is why some hospitals (seems American hospitals don't do it this badly) won't let you sleep when they aren't even coming to check on you.

Last Halloween in Toronto I got a (spooky) appendectomy, and although they were not coming to check on me, I could not sleep because I was in a loud room (the patient beside me had his whole immediate family watching over him, and my mind was awake, trying to decide whether they were speaking Brazillian or Portuguese) with bright overhead lights. I normally sleep with earplugs, but in the sort of rush I was, getting in the ambulance, I neglected to bring a pair. I managed to flag down a nurse to get me a pair of earplugs after five hours of trying to get to sleep.

If they have to come check on you, they could at least make it possible to rest when they're not checking on you.