Audio Normalization - Loudness Normalization

Loudness Normalization

Another type of normalization is based on a measure of loudness, wherein the gain is changed in order to bring the average amplitude to a target level. This average can be a simple measurement of average power, such as the RMS value, or it can be a measure of human-perceived loudness, such as that offered by ReplayGain and EBU R128.

Depending on the dynamic range of the content and the target level, loudness normalization can result in peaks that exceed the recording medium's limits. Software offering such normalization typically provides the option of using dynamic range compression to prevent clipping when this happens. In this situation, signal-to-noise ratio and relative dynamics are altered.