Sound button triggers?

Hi, I have put in a page turn sound on my slide master and a button with a trigger so people can turn this page turn sound on and off, however i cannot seem so get these to link so people can click teh button and turn the sound off. I was told to put the sound on the master and the button so it showed on every page because i have videos in teh course i'm creating and people turn the volume up for teh video then teh page turn sound is annoying. could someone tell me how i can set up the page turn sound so it can be turned on and off.

Thanks.

1 Reply