normalization confused

[rewdn]

I have been searching through the forums to determine how Audacity normalizes in what appears to be a single pass. Most normalization processes require two passes. A reading level pass and an adjusting peaks pass. Audacity appears to process only one adjusting pass. Can anyone clear up my confusion?

[steve]

It seems that Audacity keeps a "mental note" of the peak audio level of each track all the time. If you use "Amplify" you will notice that Audacity immediately knows how much the track can be amplified without clipping (much like with "Normalise".

[rewdn]

It struck me that it would make sense that Audacity was creating a audio file, so why wouldn't it already have the information. Thanks for the help.

[steve]

... so why wouldn't it already have the information.

That's what I was saying - it looks like Audacity does already have the information, and can therefore normalise in a single pass.