Here is a pastebin of the full MicrophoneAudioSource.java:
http://pastebin.com/m30138a6a
An irc discussion about the media api brought me to this:
(11:05:39 PM) d0netsFN: im interested in his method, so you think it
would work?
(11:05:47 PM) d0netsFN: all i have read is complaints about the media
api
(11:05:57 PM) d0netsFN: and people wanting javax.sound
(11:06:40 PM) andyross: d0nets: it works fine. It's a native thing,
so you need to get a native build environment working. But the
AudioTrack API is really simple: create the object and register a
callback. The library spawns a thread to fetch buffers and hand them
to the callback to fill as needed.