Abstract: The invention relates to a method and a device for determining and monitoring the degree of narcosis in a subject. The determination proceeds as follows. Auditory stimuli are generated by means of a stimulus generator (1). Response signals which signalize the response of the auditory chain to said stimuli are picked up by means of electrodes (4) on the patient's head (3). The response signals are converted by a digitizer into digital response signals. For each digital response signal, an implementation is generated by selecting a portion of the digital response signal. A signal processing means (7) is arranged, by means of which a first and a second mean signal of implementations is formed and by means of which the second mean signal is adapted to the first mean signal for forming an adapted mean signal. Finally, a waveform estimate of the adapted mean signal is formed with the aid of the signal processing means.