multiple audio html : auto stop other when current is playing with javascript

you can use event delegation. Simply listen to the play event in the capturing phase and then pause all video file, but not the target one:

document.addEventListener('play', function(e){
    var audios = document.getElementsByTagName('audio');
    for(var i = 0, len = audios.length; i < len;i++){
        if(audios[i] != e.target){
            audios[i].pause();
        }
    }
}, true);