edmontondown 发表于 2013-1-2 23:56 2 a# |- _* `8 z$ b) y& C9 _0 E
yes, may have something fell down on the other end of the hood vent
. j0 w1 R8 ^: b' oAt 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.