Check against an enum to trigger audio

Get guys and girls,

So, I’m making a side scroller in Paper 2D, and what I’m trying to achieve is that whenever the player is standing on a certain surface it plays a certain music file.

Currently I have a tick running into a line trace, that that detects what surface you are standing on, and then selects the appropriate surface. I know this is working because a print string always returns the correct surface from the enum…

My problem is that because this is being checked with the Tick, its playing the audio file over and over again every time the Tick passes and resulting in many files playing at the same time. So my question is how can I constantly check what surface the character is on, while only playing one audio file while he is on that surface, and then change the moment he steps or jumps on a different surface?