Simply add audio files into the audio folder, and add an entry into the "sounds" array in index.html
Then, open index.html in your browser and you should be good to go.
Sound1.mp3 from http://soundbible.com/2183-Slot-Machine.html Sound2.mp3 from http://soundbible.com/2148-Chinese-Gong.html
{
"name": "Crowd (Generic)",
"src": "crowd_sounds.mp3",
"loop": true,
"volume": 0.2
},