FM video signals are pre-emphasized at the uplink site and de-emphasized within the satellite receiver. At the uplink, the video signal is passed through a network that attenuates only the lower frequencies effectively boosting the high frequency portion of the signal. At the receiver, a de-emphasis network attenuates the upper frequencies to restore the original video waveform. The objective of this technique is to improve the signal-to-noise ratio by about 2 dB. This method is effective because the noise in an FM satellite transmission increases from the 0 MHz to the upper limits of the baseband signal, about 6 MHz (a triangular noise distribution). Pre- and de-emphasis reduces noise by lowering the higher power, higher frequency noise.e- and de-emphasis circuits are simple RC networks with time constants usually of 50 or 75 microseconds. Pre-emphasis and de-emphasis are also applied to audio signals, also typically with 50 (North America) and 75 (Europe) microsecond time constants. European broadcasts are also in J17 audio format.

Typically, prior to some process, such as transmission over cable, or recording to phonograph record or tape, the input frequency range most susceptible to noise is boosted. This is referred to as "pre-emphasis" – before the process the signal will undergo. Later, when the signal is received, or retrieved from recording, the reverse transformation is applied ("de-emphasis") so that the output accurately reproduces the original input. Any noise added by transmission or record/playback, to the frequency range previously boosted, is now attenuated in the de-emphasis stage.

The high-frequency signal components are emphasized to produce a more equal modulation index for the transmitted frequency spectrum, and therefore a better signal-to-noise ratio for the entire frequency range.

Emphasis is commonly used in FM broadcasting and vinyl (e.g. LP) records.