Hi, 

In this tutorial I just going to tell you how to record audio in android

initialise media player instance 
private MediaRecorder mRecorder;

record audio function 

public void startRecord() {
File fileFolder = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS), "inward");
            fileName = new File(fileFolder, "inward_rocording.mp3");
            if (!fileFolder.exists()) {
                fileFolder.mkdir();
            }

            if (!fileName.exists()) {
                try {
                    fileName.createNewFile();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            mRecorder = new MediaRecorder();
            mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
            mRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
            mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);
            mRecorder.setOutputFile(fileName);
            try {
                mRecorder.prepare();
            } catch (IOException e) {
                Log.e("Recording failed", e.getLocalizedMessage());
            }
            mRecorder.start();
}

stop record function
public void stopRecord() {
  mRecorder.stop();
        mRecorder.release();
        mRecorder = null;
}