edmontondown 发表于 2013-1-2 23:56 R7 r% l# }4 `4 u/ H
yes, may have something fell down on the other end of the hood vent
H L2 C! S; ~7 q( y/ E' b
At 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.