Found this on Military Morons, and it's what I'll be doing with my replica Sordins when they get here:
Wearing the FAST with headsets - This is a real neat feature built into the FAST. First, the top comfort pads are positioned in the shell so that there is enough room for the headset band to fit between them. The front of the fitband has two T-studs which ride in channels in the front impact liner. By pulling the center of the fitband away from the front impact liner, the studs are drawn towards the center and the front of the fitband can be detached from the impact liner. The headset band is then slid behind the earphone band and the front if the fitband is re-attached and locked in place to the front impact liner. The headset band remains behind the fitband, and the headset is essentially attached to the helmet. They are donned as a unit, instead of putting on the headset before the helmet. For stand-alone use, the headset is easily and quickly detached from the helmet. The photo below illustrates how the headset headband is captured by the fitment band.
