I want to amplify portions of a 9 hour recording. It opens and plays in Audacity perfectly well and the tools such as Noise Reduction seem to work.
I can drag-select almost any portion of the work and Effect > Amplify to get (what seems to be) a valid correction. The portion gets louder.
What I can’t do is select the work so that one end of the selection snaps to the end of the performance and forms a yellow line.
Effect > Amplify fails.
Audacity 2.2.0
Mac OS-X 10.9.5
Translation: there’s a very loud sound (0dB) at the very end, which you can’t see unless you zoom-in on the end.
It’s probably the click noise when the recording device was switched off, (there’s one at the very start).
The loud clicks can be deleted by zooming-in on them, selecting them, then pressing delete key.
You also get an unwanted saturated loud click near the very when you use Timer Record (I use it to record streaming audio from the interweb). Oddly it does not happen every time - just most times AFAICT.