That definitely sounds like a bug, though given it doesn't happen on other platforms it is almost certainly a unity bug and not one I can fix myself. The next update will have audio volume controls so you should be able to mute the sounds if they are annoying, though obviously that will have an impact on your ability to play the game (the spectrograph display is based on the in-game audio. I'll look into alternatives to that though).
Sorry for the trouble, but I don't think I'll be able to stop the squeaking.