Animate CC audio controls using javascript on button click in HTML5 canvas

I'm struggling with finding the right combination of code, or perhaps this is complete user error as I'm not a coder nor savvy in javascript... But I'm searching for a way to use a button to stop a looping sound from continuing after being clicked in a HTML5 canvas document. Upon click, the current movie clip animation stops (the video) and a new movie clip starts. Right now, the sounds are overlapping and the looped sound just doesn't stop.

Any help would be much appreciated!