Multiple audio files on the same navigation page
I have a navigation/landing page set up with four graphical buttons that allow the learner to navigate go to four separate sub-pages.
When the user starts the course from the navigation page I'd like 'audio file 1' to play. They then press button 1 to go to sub-page 1 - but when they return to the navigation page I'd like 'audio file 2' to play without 'audio file 1' starting up again. They then click button 2 to go to sub-page two, and when they return to the navigation page then 'audio file 3' begins to play and so on and so on...
Does anybody know how I can achieve this? I'm really struggling!