edmontondown 发表于 2013-1-2 23:56 & C& G5 w8 E& Z' C! e
yes, may have something fell down on the other end of the hood vent
7 Z8 V$ I/ v$ x
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.