Darkstar Thresh audio bug

When ever I use the Darkstar Thresh skin enter the game run straight to the river and place a ward in the small bush and for reasons beyond me Thresh say's something and the audio goes from volume level 1 too level 10000000000 haha. Was a bit of a surprise as I am a headset user. No other audio changes in game and nobody else can hear it. Only seem to do it from red side and has happened to me last 3 games on red side and has happened in the past. Not sure if its some kind of Easter egg?? :)