What is the issue to load audio on iPad by using Angular JS

Thanks to all in advance. I have used following script into left sidebar to load audio on each page

var vid = document.getElementById("audioplay");vid.volume = 1.0;vid.load();

I have added one audio sound in left sidebar of my website and this file included into all pages also used preload function to load the audio and it's working on PC but not load on iPad and iPhone. Can any one help me to resolve this issue