code: protected void addToPlayQueue (SoundKey skey)
      {
          boolean queued = enqueue(skey, true);
          if (queued) {
              if (_verbose.getValue()) {
                  log.info("Sound request [key=" + skey.key + "].");
              }
  
          } else /* if (_verbose.getValue()) */ {
              log.warning("SoundManager not playing sound because too many sounds in queue " +
                          "[key=" + skey + "].");
          }
      }
docs: Add the sound clip key to the queue to be played.