Planet Earth emits natural radio waves in the very low frequency range from 100hz ~ 10khz. However, as these are of a radio-wave origin they are
unable to be heard by us humans without being converted into an audio signal first. I happened across a site where the author did just that,
converting these Low radio frequencies into audio frequencies and presents various audio files capturing the sounds of magnetic earth. Fascinating
sounds from areas predominantly around Canada's northern lights.