A method and device for processing an echo signal received from an acoustic sensor. The echo signal is detected over a measurement time interval. A minimum value is ascertained, which describes a minimum amplitude of the echo signal within the measurement interval. An amplitude value is ascertained, which describes an amplitude of the echo signal within a measurement window. The measurement window is a predefined time interval within the measurement interval. A difference is ascertained between the minimum value and the amplitude value. A determination is made whether the echo signal comprises an interference signal of the first type or an interference signal of the second type, based on the ascertained difference.