The extra sound is really upon moderate to hard acceleration. It's more of a vibratory sound than the rumble type sound you get from the exhaust note.
I can't really say it's sound more than it really being vibration. It is low frequency resonance that is happening. The reason, as I said earlier, is because of the stock tube's chambers but the theory on the MIT is that it smooths the airflow to the intake. Much like mandrel bending has done for the exhaust market. The stock tube supposedly has more air disturbance to it with these chambers added.
Adding the MIT does open up a little space on the front PS of the engine compartment though.
