How to play 2 different tones on the earphone jack using AudioTrack in android

Question

I have a need of playing 2 different tones of different frequency in the earphone. I was trying with AudioTrack class, and was able to do MONO and was not able to do in STEREO mode. I want to play a tone for 50 micro second and stop for next 50 micro second, and this has to keep repeating in a loop. In right other tone has to keep playing.

I was not able to work with STEREO, please help. If any other method please suggest.

Here is the code that i tried for MONO.

import android.app.Activity;
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioTrack;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class ToneGenerator extends Activity  implements OnClickListener{

    AudioTrack audioTrack;
    Button button;
    private final int duration = 3; // seconds
    private final int sampleRate = 8000;
    private final int numSamples = duration * sampleRate;
    private final double sample[] = new double[numSamples];
    private final double freqOfTone = 10000; // hz

    private final byte generatedSnd[] = new byte[2 * numSamples];

    Handler handler = new Handler();



    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        button = (Button) findViewById(R.id.button1);
        button.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        if(v.getId()==R.id.button1)
        {
            onResume();
        }
    }

    @Override
    protected void onResume() {
        super.onResume();

        final Thread thread = new Thread(new Runnable() {
            public void run() {
                genTone();
                handler.post(new Runnable() {

                    public void run() {
                        playSound();
                    }
                });
            }
        });
        thread.start();
    }


    void genTone(){
        // fill out the array
        for (int i = 0; i < numSamples; ++i) {
            sample[i] = Math.sin(2 * Math.PI * i / (sampleRate/freqOfTone));
        }

        // convert to 16 bit pcm sound array
        // assumes the sample buffer is normalised.
        int idx = 0;
        for (final double dVal : sample) {
            // scale to maximum amplitude
            final short val = (short) ((dVal * 32767));
            // in 16 bit wav PCM, first byte is the low order byte
            generatedSnd[idx++] = (byte) (val & 0x00ff);
            generatedSnd[idx++] = (byte) ((val & 0xff00) >>> 8);

        }
    }



    void playSound(){
        final AudioTrack audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
                sampleRate, AudioFormat.CHANNEL_CONFIGURATION_MONO,
                AudioFormat.ENCODING_PCM_16BIT, generatedSnd.length,
                AudioTrack.MODE_STATIC);
        audioTrack.write(generatedSnd, 0, generatedSnd.length);
        audioTrack.play();
    }
    }