There are special places in the magnetosphere where the plasma and the magnet of the earth make light and cause sounds on telephone and radio.

The first sounds we heard over the radio were caused by the plasma bouncing back and forth in the magnet of the earth. The plasma then makes the radio or telephone sound like those back and forth motions.

The whistler sounds were caused in the part of the magnetosphere shown. The plasma here causes the high pitched sounds to be heard before the lower pitched sounds so that what you hear sounds like a whistle.

In the lion's roar region, the plasma bounces back and forth causing the radio and telephone to sound like a roaring lion. Here the signal lasts about 2 seconds and has a low tone or pitch.

Lion's Roar Audio