I have to come clean and admit that I haven't actually successfully used PARSEC yet. It's a consequence of blogging in the mornings on European time, when hardly anyone (even the Europeans) is around. PARSEC is on the InterSection sim.
However, from what I have read, it isn't a million miles away from the Ice Caves that I set up in Nemesis in 2006 and in NCC in 2007 and which are still to be found underneath my shop in NCC. The idea is that sounds are triggered by the avatars... in my case the triggers are physical, and brushing against the stalagtites and stalacmites triggers the sound, in the case of PARSEC the groundbreaking part is that the voice system triggers the sound.
It's an interesting idea for those of us who can use voice, and it's pretty unfair to judge something I haven't seen working as it is designed to work, with seven avatars all taking part. If I get to see that I will report back, but in the mean time if you can gather six friends, and cope with reading a nest of notecards, then PARSEC is waiting for you.