Corazon,
<!DOCTYPE html>
<html>
<head>
  <title>Untitled</title>
  <meta charset="utf-8">
  <style type="text/css">
  #mybtn{
       width: 128px;
       height: 128px;
       background-image: url(http://s7.hostingkartinok.com/uploads/images/2014/02/b33ecdff35171950f356df80a6a7c3dd.png);
     }
  #mybtn.play{
      background-image: url(http://gbdou88fr.caduk.ru/images/p93_color-violin-clef-illustration-music-note-circle-33645042.jpg);
  }
  </style>
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
  <script>
$(function() {
var audio = $('#myaudio'), video = $('#myvideo'), btn  = $('#mybtn');
function play()
{
   audio[0].play();
   btn.addClass('play');
}
function pause()
{
   audio[0].pause();
   btn.removeClass('play');
}
btn.on('click',function(){
   $(this).is('.play') ?  pause() : play()
})
video.on('ended pause',play)
video.on('play playing',pause)
});
  </script>
</head>
<body>
<audio id="myaudio" loop >
  <source src="http://www.w3schools.com/Tags/horse.ogg" type="audio/ogg">
  <source src="http://www.w3schools.com/Tags/horse.mp3" type="audio/mpeg">
Your browser does not support the audio element.
</audio>
<button id="mybtn"></button>
<video id="myvideo" width="320" height="176" controls >
  <source src="http://www.w3schools.com/Tags/mov_bbb.mp4" type="video/mp4">
  <source src="http://www.w3schools.com/Tags/mov_bbb.ogg" type="video/ogg">
  Your browser does not support HTML5 video.
</video>
</body>
</html>