What audio shaping network is added at an FM transmitter to attenuate the lower audio frequencies?

In FM communication, higher audio frequencies are more susceptible to high-frequency noise during transmission. To combat this, a pre-emphasis network is used at the transmitter to boost higher audio frequencies, which is functionally equivalent to attenuating the lower audio frequencies relative to the higher ones. At the receiving end, a complementary de-emphasis network is used to roll off those higher frequencies. This restores the original audio balance while simultaneously reducing the high-frequency hiss or noise picked up during the transmission path.