Well the owners manuals says to keep the DIP switch for noise gate "off". It says to call the company if you want use it, so I have no idea when you would want to use it. A noise gate is just a squelch circuit that lives in the headset rather than the airplane panel and decides what is noise and what isn't. Since most airplanes have squelch function I am not sure when you might want it. Other than that Zulus are an ideal headset and seem to have made me an inch taller too (kidding).