code: public void recycle() {
          try {
              recycleSoundMap();
              if (soundPool != null) {
                  soundPool.release();
                  soundPool = null;
              }
  
          } catch (Exception ex) {
              Log.e(TAG, "", ex);
          }
      }
docs: release all resource. after called this method, if want to use again,
  call {@link #init()} first.