Audio not playing on load when published online

Hi all, 

I'm having an issue with playback when publishing online. A page I created has multiple audio tracks (5 short .mp3 clips with sound effects), all synched to play together in the timing panel and on page load. I have an image layer on top of the tracks (to make them invisible) I have also tried moving the image to the layer under - it made no difference. In the media preview window it all plays like it's supposed to, when I publish it - absolutely nothing, not even a beep. When I moved the image to the back and had multiple player buttons on the page it still wouldn't play neither on page load, nor simaltenuosly, tracks only played when you press play on each individual track. I also tried creating a page with a .gif or .mp4 before the page with the audio to trigger user intercation, but once it comes to the page with audio - again, not a sound. I tried loading it in mulptiple browsers - nothing. Plus I need to share it with a client and ideally it should just work everywhere, rather than come with an intrusction "Play only on mozilla firefox" 

Any ideas would be greatly appreciated!