Though I generally like the audio preview feature, I frequently find it to be triggered accidentally. Usually this happens after a keyboard event; for example, I will use a keyboard shortcut to switch desktops or close a window, which will result in my mouse cursor resting over an audio file. The preview catches me by surprise as I am not using the mouse at that time, so I'm not really aware of where the mouse cursor is.

Also, if I switch windows with a keyboard shortcut the audio preview is still triggered if the nautilus window is still visible and the mouse cursor remains over the icon. I frequently switch desktops and then immediately switch to a different window with my keyboard.

It also seems like this could happen if I close a window with the mouse and an audio file lurks beneath, but this is far less annoying as my hand is already on the mouse and my focus already on where the mouse pointer is.

Other information:
A few different small changes could each mitigate this problem for me. One would be that the audio preview could not be triggered unless it was precipitated by a mouse event. Another might be that the audio preview should only occur if the nautilus window has focus.