Admittedly, these tests are more like a "shotgun" approach. If any anomalous effect will occur it will be due to the extremely variable and random conditions rather than precise tuning of the operating parameters.
You can find attached the raw audio from the original video for more accurate analysis. The video hoster Streamable appears to degrade audio quality considerably. Keep in mind though that the AM radio in that video was also turned on and it emitted a similar noise to the one physically coming from the jar.
I never heard that noise before installing in series the coil, so it's possible it could have been caused by it. Without the coil I could never run it semi-reliably in this mode.
It was indeed quite annoying and headache-inducing (hopefully not caused by anything else emitted from the experiment).