Audio editing is the process of taking recorded sound and changing it directly on the recording medium.
Audio editing was a new technology that developed in the middle part of the 20th century with the advent of magnetic tape recording. Originally, editing was done on reel-to-reel tape machines and edits were made with straight razors and special tape to connect pieces of tape that had been cut. Audio editors would listen to recorded tapes at low volumes, and then located specific sounds using a process called scrubbing, which is the slow rocking back and forth of the tape reels across the playback heads of the tape deck.
With the development of microcomputer technology, and specifically the Macintosh, Sound Recordists were able to digitize their recordings and edit them as files on a computer's hard disk. The computer programs responsible for this task are known as digital audio editors. The earliest program to become widely used in this application was a wave editor called Sound Designer in the late 1980s and early 1990s. Sound Designer was created by a company called Digidesign who achieved early industry dominance. In recent years, however, that dominance has been challenged by a number of companies attempting to grab a portion of Digidesign's market share.
In recent years, with the growing popularity of GNU/Linux, a number of Open Source software projects have sprung up in order to develop an open source audio editing program. This movement has been bolstered recently by the development of ALSA, and the Linux Low latency kernel patch, which allow the GNU/Linux Operating System to achieve audio processing performance equal to that of commercial operating systems. The multi-platform package Audacity is currently the most fully-featured freeware audio editor.