Immediate Audio Input & Output Android

As far as I can think it can be done in a very simple way. I haven't tried it,but you try it. I think it'll work:

Create two threads one for recording another for playing. Say the threads are TRecord and TPlay.

In TRecord's run method do this :

public void run(){
        MediaRecorder mRecorder = null;
        mRecorder = new MediaRecorder();
        mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
        mRecorder.setOutputFile(mFileName);
        mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);

        try {
            mRecorder.prepare();
        } catch (IOException e) {
            //todo
        }

        mRecorder.start();
}

And it TPlay's run method do this :

public void run() {
MediaPlayer   mPlayer = null;
mPlayer = new MediaPlayer();
        try {
            mPlayer.setDataSource(mFileName);
            mPlayer.prepare();
            mPlayer.start();
        } catch (IOException e) {
            //todo
        }
}

Now on mainactivity simply create two threads. First start the TRecord thread then Tplay . Try it.

here is the code for file extension:

mFileName = Environment.getExternalStorageDirectory().getAbsolutePath();
 mFileName += "/audiorecordtest.3gp";

This is actually really tricky on Android. Google themselves have a very good (but slightly long) video explaining the issues.

They also have a page explaining their latency testing methods and benchmarks for various devices.

Essentially, stock Android can't do zero-latency audio, however there's nothing stopping hardware partners from adding the required hardware and platform extensions to do so.