I'm not expressly familiar with the sound of a gunshot, but I have heard it on several occasions before. From a few feet away, it sounds like a very sharp crack followed by echoes, so if you're hearing it from a house over the best way I could figure would be a muffled but still distinguishable crack. This, of course, depends on the firearm being used.
Also, fun fact. If someone was aiming at you you wouldn't have heard it.