Audacity 2.0.6 Windows 7
I am going to generate a lot of 15 minute long files and want to extract from them a measure of volume (rms amplitude ?) at 1 second intervals in a form that I can transfer to Excel. What I need is a figure for the volume averaged over the first second, the second second and so on (to compare the sound with some other test data). I guess I could do this by hand with Compare by selecting each second manually but that’s 900 operations per test run. Is there a way to do this that can automated?
RMS will give you an approximate idea of the volume, but “loudness” is notoriously difficult to measure because it is subjective (primarily a psychological effect / sensation).
See here about loudness: https://en.wikipedia.org/wiki/Loudness
For a mono track, run this code in the Nyquist Prompt effect using the Debug button.
If you are using Audacity 2.1.0 enable the “Use legacy (version 3) syntax” option.
(let ((s (rms s 1)))
(do ((val (snd-fetch s) (snd-fetch s)))
((not val) "Copy data from Debug window")
(format t "~a, " (linear-to-db val))))