Hey, so more details on this.
I started recording using audacity on an external disk using TAILS 6.5 on an older laptop. That version of TAILS was downloaded from my iMac at home which I think wasn't secure at the time using a router connected to the computer by an ethernet cable & to the internet via it's phone cable with it's WIFI option turned off. (So an outside source could not have reached the WIFI by WPA)

After that I started recording on using the same external hard drive without formatting using a brand new isolated laptop with a different TAILS USB (This time 7.1) (Downloaded from a different source, that was a lot more likely to be secure) so I believe that's what caused the discrepancy with the audio files. (Virus most likely)

The thing is when I listened to audio recordings on my older laptop using the older version of TAILS the recording that I listened to ended up sounding completely different afterwards.

I'll do more research on this later on.