It's coming from the side. --> ok It's coming from the room side by. --> No, better: It's coming from the room next door, It's coming from the room next to us It's coming from the upside. --> No, "upside" has a different meaning, not about location, more like "benefit". (e.g. "The upside of the rainy weather is that I tested my new umbrella") It's coming from the underside. --> No. "underside" really describes the bottom of something (e.g. "I drove over a rock and scratched the underside of my car") It's coming from the room under. --> Better: It's coming from the room below. "Under" implies more direct/closer location, e.g. "I keep my money under the bed", "He's hiding under the table" It's coming from the room above. --> ok!

It's coming from the side. Correct It's coming from the upside. It's possible to say this in some circumstances, more often you'll say "It's coming from the top" It's coming from the underside. This is possible. More often you'll say "It's coming from the bottom" It's coming from the room above. Correct It's coming from the room under. Correct. More often though, you will say "...from the room underneath/beneath" It's coming from the room side by. Incorrect. "..from the next room" or "...from the adjacent room"