Adjusting volume of recorded content?

Audacity Help Forum Windows
1

I have recorded all the chapters of my new book. When listening to it, I have noticed that there are different levels of volume between different chapters. How could I, in an easy way, change so that all the chapters have the same volume? I do not want to record them all again. Hoping for a helpful reply. I am a novice on this.

2

Well… By-ear it’s pretty easy…

  1. Run the Amplify Effect on all of the chapters/sections and just accept the default. This will normalize/maximize files for 0dB peaks. (They will all have the same peaks but they probably won’t sound equally-loud.)

  2. Listen to them all and if there’s a difference choose the quietest-sounding one as your reference.

  3. Run Amplify again on the louder tracks and enter a negative dB amplification (attenuation) to match your reference (by ear).

If you want to boost or attenuate smaller selections you can fade-up or fade-down with the [u]Envelope Tool[/u]. (It is usually best to “fade” rather than making sudden adjustments.)


But if you are going to publish the book you’ll need to get familiar with the ACX requirements and the [u]ACX Check plug-in[/u].

This gets a little complicated so I’ll just give you some background to get you started…

  • The RMS level is a kind of average and it correlates well with perceived loudness.

  • The peak level does not correlate well with loudness. (The “digital maximum” is 0dB, but ACX wants you to keep the peaks below that.)

  • When you amplify or attenuate (linearly) The peaks and RMS change by the same amount… If you attenuate by -3dB, the peaks and RMS will both drop by 3dB. This causes lots of frustration when trying to get both the peak & RMS levels in spec.

  • Compression and/or limiting can be used to bring the peak & RMS closer together. But, since these techniques are normally used to bring-up the quiet parts, they also bring-up the background noise level.

3

What he said.

If you publish with ACX, they have some stiff requirements for sound quality. If you’re doing it as a free-wheeling podcast, then close is usually pretty good.

Let us know.

Koz