code: public void addEarCommand(boolean earOn) {
          StringBuilder buf = new StringBuilder();
          buf.append("(ear ");
          if (earOn) {
              buf.append("on");
          } else {
              buf.append("off");
          }
          buf.append(')');
          fifo.add(fifo.size(), buf.toString());
      }
docs: Trainer only command.
  It turns on or off the sending of auditory information to the trainer.
  
  @param earOn True to turn auditory information on, false to turn it off.