A sensor system includes a receiver circuit including a receiver electrode, a transmitter electrode, and control logic. The control logic is configured to determine that an amplitude of a transmitter electrode output signal is greater than an amplitude threshold. Based on this determination, the control logic is configured to whether a frequency of the transmitter electrode output signal is within an allowed frequency range. Based on a determination that the frequency of the transmitter electrode output signal is not within the allowed frequency range, the control logic is configured to determine that noise is present in the system.