This answer wasn’t that easy to come by, so I thought I’d blog it here in case anyone else has this problem.
I was listening to an audiobook on my iPod touch while cleaning and moving around a lot. Somehow, the audio automatically sped up and never slowed down.
After a few Google searches, I pieced together the following solution:
1) Put on the audiobook and press play.
2) Shake your iPod touch.
3) Look for a little white box with [2x] or [1 1/2x] that appears in the upper right-hand quadrant of the screen.
4) Touch that box until the icon for normal speed [1x] appears.
I hope this helps! This was really annoying to me for about a week until I had the time to work on it!