edmontondown 发表于 2013-1-2 23:56 9 e; j$ k7 K! [/ K- N f
yes, may have something fell down on the other end of the hood vent
7 J( B. H- J/ G3 z7 BAt the other end(outside) of the vent duct, there is usually a metal cover for the opening, it can swing up and down and if it is a windy day, it will be blown swinging, thus making a kind of banging noise.