Playing Audio in HTML5

Hello,

I am having problem with playing audio in Safari.

Case 1: I have 1 slide, which have 2 buttons : A, B.

-Button A has trigger to "play media 1 when user clicks",

-Button B has trigger to "play media 2 when user click".

It works well on PC, but on Safari - Ipad, on this slide, only one button works (button B), when tapping on the other button, it shows loading icon for a while but nothing happened after that.

Case 2 : I have 1 slide, which have 2 buttons : A, B.

-Button A has trigger to "play media 1 when user clicks" and "stop media 2 when user clicks",

-Button B has trigger to "play media 2 when user click" and "stop media 1 when user clicks" 

In this case, no button works when viewing in Safari : when tapping on the buttons, it shows loading icon for a while but nothing happened after that.

Anyone can help to resolve my cases ? Is there any way to combine media 1 and media 2 into 1 audio file, then create a trigger to play the audio file from the middle of the file when user clicks buttons ?

Thanks in advance

Anh