No worries. It's probably not helped by the fact that RF starts at around 20 KHz in EM at the same frequency where human hearing range ends in sound waves. So i

No worries. It's probably not helped by the fact that RF starts at around 20 KHz in EM at the same frequency where human hearing range ends in sound waves. So it's fairly easy to read a bunch of statements about frequency ranges and then mix up mediums, especially when EM contains a bunch of seemingly very different things, light, RF, xrays etc.