The hill start assist mode is one of my favorites options in the Acura. It really comes handy very often whenever you are stopped in a slope of any kind.
The noise most likely comes from the brake pads snapping back to place after the assist mode applies the brakes to avoid going backwards and then going forward after accelerating. I will assume the noise will occur more often, or more noticeable, when the pads are worn or at it's middle life.
2011 Pearl White MDX Advanced
... OEM towing, 20 mm wheel adapters,
... rails/crossbars, black wheel well trims,
... side windows acrylic deflectors,
... Michelin Latitude Diamaris HP 285/45R19,
... Full size spare tire,
... 6000 Kelvin HID's
2010 Acura TL Tech.
2001 Mercedes ML 320
2005 Mercedes ML 500 AMG Package