A method for detecting and automatically selecting an input signal in a hearing aid in which at least two analog input signals are available, comprises the steps of analyzing the analog input signals and detecting, for each analog input signal, whether it comprises a relevant signal, selecting, according to results of said analysis, at least one selected input signal that comprises a relevant signal for further processing, and controlling a signal routing means to selectively route each one of the at least one selected input signals to further processing means. A hearing aid according to the invention comprises means to perform the above method.