What is Audio normalise? How it work?

i Dont know about the audio normalise.. How it work? please give me any example code?

i used R2013a release

[Walter Roberson]

There are different things that could mean. See one at https://www.mathworks.com/help/audio/examples/loudness-normalization-in-accordance-with-ebu-r-128-standard.html but see also https://www.mathworks.com/matlabcentral/answers/56348-made-normalization-on-wave-sound#answer_68257

[keshav poojari]

[x, fs] = audioread('aa.mp3');
[loudness, LRA] = integratedLoudness(x, fs);
fprintf('Loudness before normalization: %.1f LUFS\n', loudness);

target = -23;
gaindB = target - loudness;
gain = 10^(gaindB/20);
xn = x.*gain;
audiowrite('RockGuitar_normalized.wav', xn, fs);

[x, fs] = audioread('RockGuitar_normalized.wav');
loudness = integratedLoudness(x, fs);
fprintf('Loudness af
ter normalization: %.1f LUFS\n', loudness);

The above code related to version R2018a ... But i used R2013a... so some functions are not worked .. it produce errors.

Undefined function 'integratedLoudness' for input arguments of type 'double'.

Error in silence1 (line 2)
[loudness, LRA] = integratedLoudness(x, fs);

[Walter Roberson]

There is a bit of discussion of the algorithm at https://dsp.stackexchange.com/questions/52228/integrating-values-in-a-matrix-in-matlab-audio-loudness-meter . There is a useful discussion of the topic at https://kokkinizita.linuxaudio.org/papers/loudness-meter-pres.pdf