It sounds like you have a house made of hollow concrete block. Possibly most of the block was filled with concrete, however the hollow sound may be from a block that did not get filled. It is unlikely that the crack caused the block to move, more likely the block moved due to lateral earth pressure, causing the crack. You should bring in a professional with expertise in foundations to determine how much movement has occurred, if it is serious, and what options you may have for repair. Movement in concrete block walls is pretty common, and there is an entire industry devoted to repairing block foundation issues.