To get to the english audio you have to hold the sound button down for a long while, then when you hear the sound indicating transition, let go. Do that a few times (three I think, from the original factory settings at least?) to get to the english audio. Once in the english mode, pressing the button once as normal switches between the sounds. If it doesn't work even doing that though, then yeah, something is definitely wrong. Others have reported issues with the sound box, too.