ACX, then noise floor, and pauses greater than 0.5 seconds

[Trebor]

@ProfoundP

Here’s a clean sample, rerecorded this morning after a clean reboot and turning off all of the mic’s internal processing systems. The spectrum at least looks a little more complete.

Still nothing above 9kHz …

There can be more than one layer of audio enhancements and they can be on by default … https://forum.audacityteam.org/t/audacity-as-reverb-detector/52902/5 . Audio enhancements go by names such as: MaxxAudio, DTS, Dolby, HP Sound. If you Google-search the make & model of your computer that may reveal if it has such enhancements.