A filtering technique used at a receiver to attenuate high frequencies that were artificially boosted prior to transmission. This process reverses the pre-emphasis applied at the transmitter, which is done to overcome high-frequency noise in the transmission medium. The combined process improves the overall signal-to-noise ratio, particularly in FM radio and analog audio recording.
Heard on the job
The audio sounds excessively bright and hissy because the receiver circuit is missing the required 75-microsecond de-emphasis network.