An apparatus for furnishing an amplified sensor signal of a knock sensor, encompassing an analog amplifier for amplifying the sensor signal in accordance with a first definable gain factor; an analog/digital converter for digitizing the amplified sensor signal into a digitized sensor signal; a digital amplifier for amplifying the digitized sensor signal in accordance with a second definable gain factor; and a control unit in order to furnish the first and the second gain factor as a function of a baseline sound level of the sensor signal, the baseline sound level corresponding to the component of the solid-borne sound signal generated in normal operation without knocking.