Exporting Sprectral data consistently

I am attempting to compare a single wave form to determine if our audio system is operating consistently or if renegade changes are being made. To test my theory, I have a recorded waveform that I am using as a threshold. I import my threshold waveform and export its spectral data. Then without any changes I reopen the same threshold waveform and export the spectral data again. I expected that these two exports would be identical, but I am finding that the are not.

However, if I create a chirp sound and export it, then create a second chirp sound and export it as well, those to export files match identically.

How can audaity give me different spectral export data for the exact same file / settings?

Please provide the information requested in the pink panel at the top of the page.

You appear to have read https://forum.audacityteam.org/t/spectrum-comparisons/38867/1 Did you modify the waveform in any way after importing it a second time?

Is it a WAV file or a lossy format? You could attach or provide a link to your threshold waveform. See How to post an audio sample.


I am running version 2.1.0
Win7 Home Premium SP1.
I downloaded the .exe.

Oddly, I just got this to work perfectly, albeit I dont know what changed. Obviously I am doing something different. So I need to slow down and track my steps as I work through it a few more times to see why I am inconsistent in my resiults.

In both that thread and this one, the implication is that exactly the same audio is being analyzed with exactly the same settings producing different results each time. As far as I’m aware that is impossible. If I analyze exactly the same data with exactly the same settings then I get identical results every time.

Here’s an example:

Imported 1:
spectrum1.txt (11.8 KB)
Same file imported again:
spectrum2.txt (11.8 KB)
If the results are different, then either the audio data is different, or the selection is different (so the audio is different), or the settings are different. I can think of no other explanation.