A device dedicated to processing analog knock signals delivered by a sensor of an internal combustion engine coupled to an engine monitoring unit, includes processing elements for converting values of the analog signals acquired by the sensor at known instants into representative digital samples, then for temporarily storing the samples whose acquisition instants are contained in a chosen time window, and for applying chosen digital processing operations to these stored samples so as to deliver a digital output signal representative of the knock of the engine during this time window. The processing elements are responsible i) for applying a chosen digital preprocessing operation to the stored samples whose acquisition instants coincide with instants of occurrence, and ii) for adapting at least one of the digital processing operations according to the number of stored samples that are the subjects of a coincidence.