Did you or anyone else invite them in? A noise complaint is a legitimate reason to rap on your door but most good cops won't barge on in for something as lame as that. If you're being detained then they, unfortunately, have the right to demand your name thanks to the scumbags at SCOTUS. Just walking into your house because of a noise complaint would be extremely gestapo although possibly legal.
Silly trite and erroneous position.
I wonder HOW exactly you folks imagine a police officer is SUPPOSED to get John Q. Citizen to comply with the law (when a neighbor complains about the racket) if they cannot walk into the house through an already open door?
The law is actually not crystal clear on this. But the question often gets asked "well, if they were not permitted to walk in, uninvited, under those circumstances, exactly WHAT were the officers supposed to do?"
The TEST -- the touchstone of the Constitutional analysis on police conduct -- is quite often found in ONE word. It's a word derived from the Constitution itself. Reasonableness.
I am FAR from ready to stake out a claim that a police officer is powerless to do anything about Grandpa blaring his tunes DESPITE a noise ordinance and despite a citizen complaint UNLESS the person allegedly violating the law IN THEIR presence invites them into his home.