Plot Spectrum Analysis

[Shannon]

It is still producing audio in a range that is ultrasonic, but the frequency analysis diverges, which means there has been some sort of alteration and with the nature of the audio being what it is, we cannot know what is different, and must therefore presume it may no longer be effective. So we will gladly get you new copies, but if you are loading them into software that alters them, it may happen again.

I recommend that when you get the new copies, that you set aside a folder for the ones you just downloaded and then work with copies before loading them into anything. And before anything else, load them into Audacity and verify the desired frequency analysis plot.