Audio Toggle,Toggle Audio After Game Object Is Enabled

I have a scene where in a small town a gui button enables a festival, so that the player can toggle between the village with and without a festival, I have 2 audio sources for ambience, one of a park ambience for when the scene starts, and one of a crowd ambience for when the festival is toggled, My problem is I only want the crowd audio to play when the festival game objects are toggled on, and thus far can't quite figure out how to do that.