Faster load time

Hi guys, I was handed a smal project in which they wanted the flash ad to have a sound button that would mute/unmute the sound while the video kept playing. I had to make an mp3 of the audio and use it as a sound object and calculate the start time by which frame the movie is on and the frame rate. It works just fine and even has a preloader but now the client is asking if there is a way to buffer and start playing it before the whole thing is loaded up? How can I do this?