A hearing apparatus has a microphone for converting ambient sounds into a microphone signal, a signal processor for processing the microphone signal and an output transducer for outputting an output signal. A characteristic voice measure is ascertained for a voice component in the ambient sounds, and a supplementary measure characteristic of an activity of the wearer of the hearing apparatus is ascertained. Subsequently, an evaluated correlation between the voice measure and the supplementary measure is used to increase a probability value for the presence of a communication situation between the user and a third party if the voice measure and the supplementary measure, under at least one prescribed criterion, assume a value representative of the presence of the voice component and of the activity of the wearer. The probability value forms the basis for altering a signal processing algorithm that is executed to process the microphone signal.