(1) Generally, the process of equalizing a signal to increase the content of a desired frequency band before the signal is sent to another device. (2) A type of high-frequency boost applied to signals about to be broadcast on FM stations or recorded on tape to reduce the apparent noise level. Pre-emphasis brings the high-frequency content of the music up to a level further above the ambient noise level, of the recording medium. In order to restore the proper balance of high and low frequencies to the reproduced music signal, the boost added by pre-emphasis must be removed by a complementary cut, called de-emphasis. See equalization curve.