The internal variables are to prevent crashes when an unitialized <audio> tag is accessed. (Initializing the tag takes non-negligible amount of time.) Please see comments in the source code (Ctrl+F "mirror") for more info,

To illustrate, the following code will yield an exception; the values will not be initialized as desired. Code proposed in this PR, however, will behave as expected, due to the mirroring.

var sound = Ti.Media.createSound({url: 'sound.wav', time: 3000,volume: 0.8});
	sound.play();