android 录制pcm 播放pcm

我在Android1.5上面用AudioRecord录制pcm时，用AudioTrack播放出来的全是噪音，以下是源码，谁做过这方面的，帮我分析一下。

录制：

int minBuffSize = AudioRecord.getMinBufferSize(8000,

AudioFormat.CHANNEL_CONFIGURATION_MONO,AudioFormat.ENCODING_PCM_16BIT);

AudioRecord mAudioRecorder = new AudioRecord(MediaRecorder.AudioSource.MIC, 8000,

AudioFormat.CHANNEL_CONFIGURATION_MONO,

AudioFormat.ENCODING_PCM_16BIT, minBuffSize*3);

//开始录音

mAudioRecorder.startRecording();

byte[] mBuffer = new byte[minBuffSize*3];

//从MIC获取音频数据到mBuffer中

int len = mAudioRecorder.read(mBuffer, 0, 1200);

播放：

int iMinBufSize = AudioTrack.getMinBufferSize(8000,

AudioFormat.CHANNEL_CONFIGURATION_STEREO,

AudioFormat.ENCODING_PCM_16BIT);

AudioTrack audioTrack=new AudioTrack(AudioManager.STREAM_MUSIC, 8000,

AudioFormat.CHANNEL_CONFIGURATION_STEREO, AudioFormat.ENCODING_PCM_16BIT,

iMinBufSize, AudioTrack.MODE_STREAM) ;

audioTrack.play();

audioTrack.write(data, 0, data.length);