A hearing aid to be placed in the auditory canal. This hearing aid is composed of one side that is fitted near the outside of the ear and another side that has to be fitted facing the eardrum. The two sides are connected to each other by way of a curvature. This curvature is such that the hearing aid can be used either on the left or on the right by further special measures such as central positioning of the microphone input in the head end face of the one side, making use of only two angles of curvature of approximately 15.degree. and approximately 45.degree., and using switching means. In this way it is possible to provide a hearing aid that can be used either on the left or on the right.