what sound update? do you know anything about the miles sound system that is being used now? you might want to look into it so you know what you're talking about...and make sure you're headphones are compatible.
We're talking about using a different sound file for outside the cockpit, rather than just using one "Eng" (+Engoff, Engstart...) file for both inside and outside. If you look in the advanced sound options, there
are external sounds listed, but they all source the same file.