edmontondown 发表于 2013-1-2 23:56 % k. P; W L& m: n# ~yes, may have something fell down on the other end of the hood vent
, M% _7 ^2 ^: [& |2 a$ ~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.