Don't say harp around my father or he will put on his tin-foil hat. I researched these sounds and videos a while back. Nice to see some sort of answer.
... yea, actually, there where even acoustic researches in many physical-chem. processes, mostly for energetic value definition - the polar plasma shows too, as the lab.-based plasma tests (doe, all out of our senses reach - in fact, we could have some issues if it would be in those frequency because the baseline chaos). So yes - HARRP does play a lot white the plasmic ionosphere - but this was mostly Suns play.
The interesting thing - you can fetch the sound of a lightning, white a good recorder - thats why you know the plasma conditions are around them (they match white lab. plasma characteristics of air). Im sure there will be much analytical tech in the future based on such kind of knowledge ...
As for your father - if youre from US/Oceania, no need to worry, works on a outer-horizon basis ( thats our side problem in terms of the iron curtain : ) ) ... he should be more weary about additives in food.
