Audio normalization

Normalization is the process in audio engineering, the amplitude of the analog or digital audio material to zoom in or out so that it is within a predetermined range. There are there are two main reasons why is normalized - for a technical framework for the transmission and storage of audio material on the other, the adjustment of loudness ( perceived by the human volume) of the material. A technical target can be auszusteuern a signal to the maximum possible amplitude to obtain a good signal - to-noise ratio and low quantization error (after reducing the word length ). An application in the field of loudness is the same to be adapted to a particular target value, as described for example in the recommendations EBU R 128, ITU BS.1770 or ReplayGain.

In Software for audio signal processing, there is usually the opportunity these mathematical operations (see also standardization) to run automatically:

• Approximation to maximum amplitude: In the audio material is sought after the point at which the signal has the largest absolute value. Then all the material is exactly the extent strengthened or weakened that this value for desired ( allowed ) maximum value.

• RMS normalization (Root Mean Square): This method is not the maximum value, but the effective value (RMS ) of the material is taken into account.

• Loudness normalization: In this method, the loudness of audio material is calculated according to a certain algorithm and takes on a particular target ( Target Level -23 LUFS with EBU R 128). Through this kind of loudness adaptation, it is possible to make a human loudness perception corresponding approximation of the loudness to adjust, for example, several pieces of music to each other or to avoid radio and television loudness jumps at program transitions.