Listening to audio book without headphones - no problem. Head phone jack plugged into computer and using headphone while I workout on Elliptical: After a bit I will hear a 3 beep sound - the same sound you hear when unplugging a USB from the computer while it is running. As more time passes the beeps become more frequent until it beeps every 3 to 4 seconds. This spoils listening to the audio book. Any suggestions???