A question about AudioParam (re)scheduling

I'm somewhat lost about the way AudioParams react to canceling/adjusting
while they are currently in a transition. I can't figure out why this
example results in clicks in the audio when repeatedly clicking the button:

http://codepen.io/anon/pen/xVGwRY

I don't see any reason why this should give me clicks, am i doing something
wrong here?


regards,
Peter van der Noord