A method of operating a sensor system having at least one proximity sensor, with regard to generating a trigger signal indicative of an occurrence of an operator-intended event in the presence of noise. The method includes repetitive steps of: acquiring the sensor signal at specified sampling times, comparing a value obtained as a presently sampled sensor signal with a presently valid first threshold value, generating a trigger signal if the value obtained as the presently sampled sensor signal is as large as or exceeds the presently valid first threshold value, omitting to generate a trigger signal if the value obtained as the presently sampled sensor signal is less than or equal to the presently valid first threshold value, forming a subset out of the sampled sensor signals, determining an update value for the first threshold value, and replacing the presently valid first threshold value by the update value.