Honestly, see if your council has environmental wardens. If you don't want to confront them, just tell the coppers or whoever that you buzzed their buzzer, knocked on their door, etc. but they didn't answer.
Your council has probably had to deal w/this. A LOT. And has procedures in place for handling widdos like that - they probably just try to act wide.
And no, the cops don't laugh, they will come out. We had a neighbour who used to wake us w/drunken Eminem karoke at 3 or 4AM. But one night, we heard the polis instead, telling them their voices sounded like nails on a chalkboard and to shut up and go to bed. We weren't the only ones who heard them!