src,mp3,m4a,ogg,wav,wma parameter for the audio shortcode

Syntax

[audio
src,mp3,m4a,ogg,wav,wma="| URL - If omitted uses first attachment"
loop="off| on - Allow looping of media"
autoplay="off| on - Causes media to autoplay"
preload="none| auto| metadata - How the audio should be loaded"]