High frequencies are shorter wavelength and closer together, like gamma X-rays.
“Middle of the road” we’ll say are the visible spectrum, longer and higher amplitude (talker waves) are linger, like infrared and get to be miles high and hundreds of mile long as they resonate into the universe, hence radio waves.
We hear the ones, audible within our capacity to hear and the super long ones picked up by radio telescopes from distant stars and galaxies.
The spectrum of energy is the range of frequencies and amplitude.
https://en.m.wikipedia.org/wiki/Schumann_resonances
