Super High Frequency is a long way from ionizing radiation, but it still carries energy. It would be helpful to know how much a 5 GHz wireless transceiver heats a quantity of water sitting right next to it. Now, if the water in your brain were heated the same amount, does this result in any biological damage? I kind of doubt that it would, as you need frequencies about a million times higher, in the petahertz range, before the radiation is ionizing.
And don’t think that using earbuds is going to help here. If you’re using wireless earbuds, the signal strength doesn’t degrade that much, and your sending that right into your head. If you’re using wireless earbuds, you’ve moved the transceivers that much closer to your brain.