Mouse Over - Play Sound Only Once

I have a "Mouse Over 9Patch" construction to trigger a sound when the mouse is in a certain area of the screen. The sound is set "not looping", but because the area is quite large it re-triggers the sound constantly until I rest the mouse fully or move out of the area.

Is there an elegant way to lock an event to a single sound instance?

Use the Trigger Only Once event with the event.

<img src="http://content.screencast.com/users/ArcadEd/folders/Jing/media/bf2530ee-1fe6-4355-b9a8-a22b47be60f2/2013-09-01_0713.png" border="0" />

Thank you, the Events are quite powerful, so I have to dig deeper in the Systems section...