외부에서 오디오가 재생되었을 때 어떻게 하면 알 수 있나요?

아래와 같이 코드를 구현해 봤는데 이벤트가 발생하지 않은것 같더라고요.

아래 코드는 외부에서 재생되는 오디오와는 관련이 없는건지...

도움말씀좀 부탁드립니다.퇴근하고싶어요......

private void initAudioManager() {
        audioManager = (AudioManager)context.getSystemService(Context.AUDIO_SERVICE);
        int streamTypes = AudioManager.STREAM_ALARM
        | AudioManager.STREAM_DTMF
        | AudioManager.STREAM_MUSIC
        | AudioManager.STREAM_NOTIFICATION
        | AudioManager.STREAM_SYSTEM
        | AudioManager.STREAM_VOICE_CALL;
                
        int result = audioManager.requestAudioFocus(audioClient, streamTypes, AudioManager.AUDIOFOCUS_GAIN);
        Toast.makeText(context, String.valueOf(result), Toast.LENGTH_SHORT).show();
    }
   
    private OnAudioFocusChangeListener audioFocusListener = new OnAudioFocusChangeListener() {
       
        @Override
        public void onAudioFocusChange(int focusChange) {
            Toast.makeText(context, String.valueOf(focusChange), Toast.LENGTH_SHORT);
            switch(focusChange) {
            case AudioManager.AUDIOFOCUS_LOSS:
                break;
            case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT:
                break;
            case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK:
                break;
            case AudioManager.AUDIOFOCUS_GAIN:
                break;
            default:
                break;
            }
        }
    };