AudioRecord延迟（Android）GT-i5700

private boolean isRecording;
private AudioManager am;
private int count;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    am = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
    am.setMicrophoneMute(true);

    while(count <= 1000000){
    Record record = new Record();  
    record.run();
    count ++;
    Log.d("COUNT", "Count is : " + count);
    }
}

public class Record extends Thread
{

        static final int bufferSize = 200000;
        final short[] buffer = new short[bufferSize];
        short[] readBuffer = new short[bufferSize];

        public void run() {  
         isRecording = true;
         android.os.Process.setThreadPriority
         (android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);

         int buffersize = AudioRecord.getMinBufferSize(11025,
         AudioFormat.CHANNEL_CONFIGURATION_MONO,
         AudioFormat.ENCODING_PCM_16BIT);

                        AudioRecord arec = new AudioRecord(MediaRecorder.AudioSource.MIC,
                                        11025,
                                        AudioFormat.CHANNEL_CONFIGURATION_MONO,
                                        AudioFormat.ENCODING_PCM_16BIT,
                                        buffersize);

                        AudioTrack atrack = new AudioTrack(AudioManager.STREAM_MUSIC,
                                        11025,
                                        AudioFormat.CHANNEL_CONFIGURATION_MONO,
                                        AudioFormat.ENCODING_PCM_16BIT,
                                        buffersize,
                                        AudioTrack.MODE_STREAM);


                        am.setRouting(AudioManager.MODE_NORMAL,1,
                          AudioManager.STREAM_MUSIC);


                        int ok = am.getRouting(AudioManager.ROUTE_EARPIECE);
                        Log.d("ROUTING", "getRouting = " + ok);
                        setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);
                        //am.setSpeakerphoneOn(true);
                        Log.d("SPEAKERPHONE", "Is speakerphone on? : " + am.isSpeakerphoneOn());
                        am.setSpeakerphoneOn(false);
                        Log.d("SPEAKERPHONE", "Is speakerphone on? : " + am.isSpeakerphoneOn());
                        atrack.setPlaybackRate(11025);

                        byte[] buffer = new byte[buffersize];
                        arec.startRecording();
                        atrack.play();

                        while(isRecording) {
                                arec.read(buffer, 0, buffersize);
                                atrack.write(buffer, 0, buffer.length);
                        }

                        arec.stop();
                        atrack.stop();
                        isRecording = false;
        }
}