Audio is the another element in java game/apps. It work as game sound. There are many type audio files like mp3, aac, wav, amr, m4a etc. But all phone does not support all format (example, Nokia 216 only support .amr and .wav type music). If you want to play mp3 file in nokia 216 by java games/apps you can't. Otherwise most of itel, samsung, motorcola and nokia nokia s40 phones supported mp3 files. So it is most important for know what type of audio file support in all java phones.