Just found this yt channel which has audio of whistlers from various space missions:<p><a href="https://www.youtube.com/user/VoyagerPWS/" rel="nofollow">https://www.youtube.com/user/VoyagerPWS/</a>
The British Antarctic Survey has collaborated with a musician to create a work incorporating these and other Sounds of Space:<p><a href="https://www.bas.ac.uk/project/sounds-of-space/" rel="nofollow">https://www.bas.ac.uk/project/sounds-of-space/</a>
So this is 1kHz radio wave (300km wave length), I didn't know they can get that low, what is theoretical limit? One of my favorite explanation of how the now-debunked em-drive supposed to work was that it produces radio waves with such a long wavelengths that it doesn't fit observable universe and that makes it push in one direction.