What's that noise?

Our neighbors were playing their music pretty loud on their back porch tonight and it had a pretty fast beat. Carter was in the kitchen when he suddenly froze and said, "What's that noise? It's my heart beating!" While I was trying to convince him otherwise (pointless) he said, "Ooooooooooooh....it stopped. Oh wait, it's beating again!" Good thing there wasn't a long pause between songs or he would have had me calling 911!