Audio normalization

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Audio normalization is the process of increasing (or decreasing) the amplitude (volume) of a digital audio recording. Typically normalization increases the amplitude of the audio waveform to the maximum level without introducing any distortion into the recording.

Specifically, normalization applies a constant amount of gain to an entire recording to bring the highest peak to a target level, usually 98% (-0.3 dB) or 100% (0 dB). This differs from dynamics compression, which applies varying levels of gain over time depending on the level of the audio source. Normalization applies the same amount of gain across the entire recording so that the dynamics are preserved.

Normalization is an off-line effect since it requires two passes. The first pass determines the highest peak, and the second pass applies the gain to the entire recording.

Normalization is often used when remastering audio tapes for CD production, in order to maximize the bandwidth on an audio CD, and to make it sound louder. It is often combined with dynamic range compression and hard limiting to increase the apparent volume of a CD.

[edit] Normalizers

• MP3Gain analyzes and losslessly normalizes mp3 audio files.

[edit] See also

• Replay Gain