[EDIT]
One should not use the FileReader API to load an user selected File into its page.
Instead one should prefer the URL.createObjectURL(File) method.
This will return a blobURI, only accessible from user session, which, in case of user File, is just a direct pointer to the original file, thus taking almost nothing in memory.
input.onchange = function(e){
var sound = document.getElementById('sound');
sound.src = URL.createObjectURL(this.files[0]);
// not really needed in this exact case, but since it is really important in other cases,
// don't forget to revoke the blobURI when you don't need it
sound.onend = function(e) {
URL.revokeObjectURL(this.src);
}
}<input type="file" id="input"/>
<audio id="sound" controls></audio>[Previous answer]
You can’t access the full url of a local file with input type="file".
However you can read the file thanks to the file API
input.onchange = function(){
var sound = document.getElementById('sound');
var reader = new FileReader();
reader.onload = function(e) {
sound.src = this.result;
sound.controls = true;
sound.play();
};
reader.readAsDataURL(this.files[0]);
}<input type="file" id="input"/>
<audio id="sound"></audio>