问java.lang.IllegalStateException in MediaPlayer

EN

final MediaPlayer[] threeSound = new MediaPlayer[1];
threeSound[0] = new MediaPlayer();
final CountDownTimer playThreeSound = new CountDownTimer(1000, 1) {
    boolean timerStarted = false;
    @Override
    public void onTick(long millisUntilFinished) {
        torgText.setText("3...");
        if (!timerStarted) {
            timerStarted = true;
            threeSound[0] = MediaPlayer.create(PlayActivity.this, R.raw.three);
            try {
                threeSound[0].prepare();
                threeSound[0].start();
            } catch (IOException e) {
                e.printStackTrace();
                Log.e("IOE", "Something went wrong");
            }
        }
    }

    @Override
    public void onFinish() {
        if (threeSound[0].isPlaying()) {
            threeSound[0].stop();
        }
        playTwoSound.start();
    }
};

FATAL EXCEPTION: main
Process: testapplication.android.com.guesstune_v2, PID: 3641
java.lang.IllegalStateException
at android.media.MediaPlayer._prepare(Native Method)
at android.media.MediaPlayer.prepare(MediaPlayer.java:1351)
at testapplication.android.com.guesstune_v2.PlayActivity$6.onTick(PlayActivity.java:316)
at android.os.CountDownTimer$1.handleMessage(CountDownTimer.java:133)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:7007)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199)