ReplayGain

ReplayGain is a proposed standard published by David Robinson in 2001 to measure the perceived loudness of audio in computer audio formats such as MP3 and Ogg Vorbis. It allows players to normalize loudness for individual tracks or albums. This avoids the common problem of having to manually adjust volume levels between tracks when playing audio files from albums that have been mastered at different Loudnesses.

ReplayGain is now supported in a large number of media players and portable media players and digital audio players. Although the standard is now formally known as ReplayGain, it was originally known as Replay Gain and is sometimes abbreviated RG.