Sorry FLL, we'll all just have to replay that sound in our minds. The new engines run a much higher speed than the old Enterprise engines. (That's why the new Caterpillar engines need the transmissions.) That cool pocketa pocketa sound only happens with low speed diesels.
One of the less known but cool things about the old engines was that there was no reverse gear or neutral for that matter. To back up, the engines were stopped and then restarted running backwards. Lots of compressed air and fancy camshafts on the engines to make this work. I'm sure it got very interesting in the engine room if they ever had to stop in a hurry with the ship moving at cruising speed...