Extra exam question E7E05

WhyA pre-emphasis network is added to an FM speech channel to boost the higher audio frequencies. A pre-emphasis network is added to an FM speech channel to deliberately boost the higher audio frequencies before transmission, working together with a matching de-emphasis network at the receiver to improve the overall signal-to-noise ratio across the audio band, answer D. De-emphasis is the receiver-side counterpart that cuts high frequencies back down, not what's added at the transmitter, and "harmonic enhancer" and "heterodyne enhancer" aren't real, standard FM audio processing terms.