Shells of hearing devices, and in particular for hearing aids, are frequently manufactured using an RSM method and battery flaps are injection-molded. Problems arise frequently due to the varying error tolerances of the two processes when the battery compartment is locked into position on the shell. For this reason a hearing device with a shell, which has a battery opening and a battery flap, which is injection-molded from plastic, is provided for closing the battery opening. The hearing device also has a module which is likewise injection-molded from plastic, on which the battery flap is pivotally supported and which has a detent mechanism via which the battery flap locks into place detachably in a closed position to prevent a pivot movement. Since the injection-molded battery flap locks into position with the injection-molded module, the error tolerances of the shell, often produced by an RSM method, play no part.