(1) In communications, techniques used to reduce distortion and compensate for signal loss (attenuation) over long distances.
(2) In audio, equalization raises and lowers frequencies to yield a desired sound. A graphics equalizer is equipment with a sliding lever for each of several frequency bands (the more bands, the finer the tuning). The user adjusts each frequency according to the music requirements (speakers, environment, etc.), as well as personal taste. When adjusting audio in the computer, software-based equalizers perform the same functions as stand-alone hardware. See
dialog enhancer.