The present invention is directed to a system and method for assessing interference to a signal caused by magnetic field. The system includes a magnetic field generator configured to generate a magnetic field. The system further includes a first magnetic field sensor configured to detect a magnetic field and to generate a first signal representative of the magnetic field detected thereby. The system still further includes a second magnetic field sensor. The second magnetic field sensor is configured to detect a magnetic field and to generate a second signal representative of the magnetic field detected by the second magnetic field sensor. The system yet still further includes a processor. The processor is configured to receive and process the second signal to determine whether said magnetic field detected by said second magnetic field sensor may cause distortion to said first signal, as well as the magnitude of such distortion.