A while back I lived near the arctic circle and would go out on my balcony (when a lack of wind allowed me to pry the door open) to watch the northern lights. I was sure that they made a weird noise... a soft swooshing sound with a bit of a hum to it.
The noise in some of the videos reminded me of them, but the noise in the videos was much louder. The auroras' sound was subtle, eerie, ephemeral... ebbing and flowing with the dance of the lights.
Gaia’s pretty lippy.
http://www.damnedct.com/the-moodus-noises/
http://www.unsolved-mysteries.com/unexplained_events/taos_hum.html