MP3 Works In Browser But Not In Final APK?

I'm working on a fairly simple web based app. Basic functionality is push a button and hear a sound. It's all done in HTML and JavaScript and then built using Phonegap Build. It works perfectly in Android's browser. But when packaged into an APK and installed on the phone, the sounds don't play.

I'm still fairly new to Android development, so I'm just looking for some direction. I downloaded a logcat viewer, found where the mp3 files are being loaded up, but nothing stands out as an error or problem. Here's the basic JS code that should play the sound.

var sounds = new Array();
sounds[0] = "0.mp3";
sounds[1] = "1.mp3";
sounds[2] = "2.mp3";
sounds[3] = "3.mp3";
function PlaySound() {
randNum = Math.floor(Math.random()*4);
var sound = new Audio(sounds[randNum]);
sound.play();
}

The PlaySound function is called when the button is tapped. I've done console logs to ensure the function is called properly.