Background audio works in Play slide but not in HTML5 (in Captivate 9 )?

Hi,

I have a slide which has a background audio and separate audio on the slide. When I preview the slide it works fine, but when I preview it in HTML 5 (Google Chrome) I can't hear the background audio at all. I've tried previewing it in Safari and I can't hear the background audio and also some of the sound files don't work either?

Can anyone help please?

Thanks