Android: How to play Tone sound

    /* Tone play sample code */        private void playTone() {        ToneGenerator tg = mToneGenerator;        if (tg != null) {            tg.startTone(ToneGenerator.TONE_PROP_BEEP2);        }      }        @Override    public void onResume() {    initializeTone();    }               @Override    public void onPause() {    releaseTone();    }           private void initializeTone() {        // Initialize tone generator.        try {            mToneGenerator = new ToneGenerator(                    AudioManager.STREAM_SYSTEM, 50);        } catch (Throwable ex) {            Log.w(TAG, "Exception caught while creating tone generator: ", ex);            mToneGenerator = null;        }    }     private void releaseTone() {    if (mToneGenerator != null) {            mToneGenerator.release();            mToneGenerator = null;        }}