If the noise happens at a particular point of each crank revolution, then (unless you are running 1:1 gearing) the problem is with either your cranks, or bottom bracket.
It is not your chain
Sorry, I've just read the OP again. Your chainwheel is bent
If the noise happens at a particular point of each crank revolution, then (unless you are running 1:1 gearing) the problem is with either your cranks, or bottom bracket.
It is not your chain
Sorry, I've just read the OP again. Your chainwheel is bent