I do not believe there is a built-in method of doing this, but you should be able to make it happen by making a dummy button of what you want to show while the audio is playing. Just place the buttons one top of each other and then use the .hide() and .show() methods to toggle between displaying the buttons. You will need to setup a function to listen for the end of the audio.
Here is an example (untested code, just showing the concept, not all code is here):
//place code behind real button
$('#m1-screen-dummy1').show(); //show dummy button
$('#m1-screen-push1').hide(); //hide real button
var aw1 = AudioPlayerWidget.fromWidget('m1-test-audio1-container');
function onEnd(event) {
$('#m1-screen-dummy1').hide(); //hide dummy button
$('#m1-screen-push1').show(); //show real button
}
// subscribe for events
aw1.events.bind('ended', onEnd);
aw1.events.bind('ended paused', function(event) { console.log(event.type); });
// unsubscribe
aw1.events.unbind('ended', onEnd);