For a hearing aid, the information for the hearing aid wearer relating to the state of charge of the power source (4, 4') or the remaining life of the hearing aid with the relevant power source (4, 4') is to be improved. To this end means are provided for operating the hearing aid by which the state of charge or remaining life can be interrogated at any time, with the information about the state of charge or remaining life being provided to the hearing aid wearer by emitting an acoustic signal indicating the state of charge or remaining life. The hearing aid wearer can thus be informed conveniently and discretely at any time about the state of charge or the remaining life.