AUltrasonic waves have no impact on electromagnetic waves. Note, however, that, if the 40kHz signal line runs in close vicinity of the ultrasonic sensor, noise from the signal line could be superimposed on the sensor signal, reducing the S/N ratio. Since the recipient sensor signal line has a high impedance, it is recommended that it be connected in the shortest possible length and shielded to minimize the impact of crosstalk and external noise.