左右声道与麦克风录音分离

我正在尝试从麦克风进行录制，并且仅将录制的数据发送到单独的左声道，而右声道则为零，但是我的技术似乎不起作用。.我在PCM 16和单声道模式下使用录音和音轨怎么办我好像做错了吗？

package com.example.leftrighttest;

import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioRecord;
import android.media.AudioTrack;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        int freq=44100;
        final int bufferSize = (AudioRecord.getMinBufferSize(freq,AudioFormat.CHANNEL_IN_MONO,
                AudioFormat.ENCODING_PCM_16BIT ));

        AudioRecord audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, freq,AudioFormat.CHANNEL_IN_MONO,
                AudioFormat.ENCODING_PCM_16BIT, bufferSize );


        AudioTrack audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
                (int) freq,AudioFormat.CHANNEL_OUT_MONO,
                AudioFormat.ENCODING_PCM_16BIT, bufferSize,
                AudioTrack.MODE_STREAM);

        audioTrack.setPlaybackRate(freq);

        final byte[] buffer = new byte[bufferSize];
       audioRecord.startRecording();




                    byte[] byteBufferFinal = new byte[bufferSize*2]; 

                    //LL RR LL RR LL RR 
                    while(true)
                    {
                    audioRecord.read(buffer, 0, bufferSize);
                   for(int k = 0, index = 0; index < byteBufferFinal.length - 4; k=k+2){
                        byteBufferFinal[index] = buffer[k]; // LEFT {0,1/4,5/8,9/12,13;...}
                        //System.out.println(byteBufferFinal[index]);
                        byteBufferFinal[index+1] = buffer[k+1];
                       // System.out.println(byteBufferFinal[index+1]);
                        index = index + 2;
                        byteBufferFinal[index] =0; //byteBuffer2[k]; // RIGHT {2,3/6,7/10,11;...}
                        //System.out.println(byteBufferFinal[index]);
                        byteBufferFinal[index+1] =0;// byteBuffer2[k+1];
                       // System.out.println(byteBufferFinal[index+1]);
                        index = index + 2;
                    }
                       audioTrack.write( byteBufferFinal, 0, bufferSize*2);
                       audioTrack.play();
                    }

    }



}