Normalize or Amplify?

[gasman]

I thought those of you who are digitalising quiet old recordings and are using the 'amplify' parameter in (say) Audacity to increase the percieved volume might like to know that it is safer to use the 'normalize' function. Amplifying the signal is more hit and miss because you need to monitor the resultant volume peak to check whether the signal has distorted in peak areas - normalisation saves the need to do this as it calculates the peak and raises it to 0dbfs, which is the loudest level allowed in a digital system.

Normalisation is traditionally used when finalising CD's in music production because it calculates the peak levels of all recordings on a CD and raises the ceiling of the recordings to 0db, which enables more consistency between tracks in an album.

Normalisation is always the final process in 'additive' audio renovation because, any other adjustments to the audio - such as using equalisation - will raise the levels of individual frequencies which are likely to result in distortion of signal.

This all sounds more complicated than it needs to be as basically all you need to remember is that if a track needs to be amplified, just choose Normalisation after all other 'additive' audio adjustments have been made. (With the exception of processes like fade in's and outs, which are 'reductive' audio processes).

Whether you Amplify or Normalize both will raise the ground level of noise and you can either 'silence' or 'cut' and length of audio before the music begins (often safer to fade the endings).

I write this as someone who has had over 25 yrs in the Audio Production field - hope this helps......... !