Some time ago I was asked by L how come the volume of her Ipod was...well, sort of having it's on life.
I told her that it has to do with altitude. If she's high up, the Ipod has to work harder in the same way that if you exercise at high altitudes, your heart has to work harder, and you get out of breathe. When the Ipod works harder, the volume goes down.
I could just have told her to take the Ipod out of her jeans pocket.
J calls me sinister.