so in firefox the audio in the tag generated by section 1 of this script displays for a few seconds and then disappears. the part in section 2, however, works just fine... I've given up on IE9 (anyone know how to even get HTML5 audio to even show up in IE9?) but all parts of this code work just fine in Chrome and Safari.. help?

section 1:
function int_quiz(){
while(int_loop<21){
var intervalfile=choose_interval();
document.getElementById('sound'+int_loop).innerHTML = "\
<div id='audio"+int_loop+"'>\
<audio controls id='1' onended='intplaycounter(this)'>\
<source src='sounds/intervals/"+intervalfile+".ogg' id='intfile"+int_loop+"' type='audio/ogg'>\
<source src='sounds/intervals/"+intervalfile+".mp3' type='audio/mpeg'>\
<source src='sounds/intervals/"+intervalfile+".wav' type='audio/wav'>\
Your browser does not support the audio element.\
</audio></div>\
<input type='text' id='user_input"+int_loop+"' value='Type answer here'\
onfocus='clearThis(this)'/>\
<button onclick='int_check_ans("+int_loop+")'>Check Answer</button>\
</form>";
int_loop++;
}
}

section 2:
function chd_quiz(chdtyp){
while (chd_count < 21){
var chd_folder=choose_folder(chdtyp),
chord=choose_chord();
document.getElementById('sound'+chd_count).innerHTML = "\
<div id='audio"+chd_count+"'>\
<audio controls id='1' onended='chdplaycounter(this)'>\
<source src='sounds/chords/"+chdtyp+"/"+chd_folder+"/"+chord+".ogg' id='chdfile"+chd_count+"' type='audio/ogg'>\
<source src='sounds/chords/"+chdtyp+"/"+chd_folder+"/"+chord+".mp3' type='audio/mpeg'>\
<source src='sounds/chords/"+chdtyp+"/"+chd_folder+"/"+chord+".wav' type='audio/wav'>\
Your browser does not support the audio element.\
</audio></div>\
<input type='text' id='user_input"+chd_count+"' value='Type answer here'\
onfocus='clearThis(this)'/>\
<button onclick='chd_check_ans("+chd_count+")'>Check Answer</button>\
</form>";
chd_count++;
}
}