A hearing aid device is provided in which wireless data transmission and reception are established between a first hearing aid and a second hearing aid, worn one on each ear, wherein in a case where wireless transmission and reception are not possible, the first hearing aid and the second hearing aid are switched from a liaison operation mode in which both hearing aids are interactively adjusted to a solo operation mode in which each hearing aid is independently adjusted. In a case where wireless transmission and reception are possible, the first hearing aid and the second hearing aid are switched from the solo operation mode to the liaison operation mode.