The appts. includes a circuit unit (S) with a transmission response which effects a signal compression. The circuit unit is supplied with the analogue input signal (U) at its input. An analogue-to-digital converter (W) is connected to the output of the circuit unit via a sample-and-hold circuit (AH). A digital correction device (K) is arranged after the analogue-to-digital converter. The digital correction device outputs a digital output signal (D) which is proportional to the analogue input signal.
