I have wrote a script with autoit to create a gui for an exercise bike i am building. It uses an i-pac 4 keyboard input board, connected to a magnetic reed switch to read the magnet on the bike wheel as it completes each rotation. eventually it will include an mp3 player and others. I have been programming this on my laptop, that has headphones plugged into it,so i never noticed it before, but for some reason i had just put my headphones in and noticed that there is a sound being played each