Wierd glitch (or something) on my Macbook pro

I have a MacBook Pro (Mid 2015) which I love but I just ran into a problem just now. I was using my Mac with my monitor plugged in and all of a sudden it started to play an audio clip (from doc and mhathi and I don't have it downloaded or pulled up on youtube so I restarted my computer then it happened again now it's not doing it. Can some one tell me what it is and help me fix it.

P.S this has only happened 1 time before