Last time i saw it, the Sight sense was just a cone-trace check from time to time, configurable. That one proved problematic in performance due to all the traces and the fact that it was O(nsquared) becouse every AI checked for every other AI, careful if you have many bots with that enabled.The sound system was a very simple system, it just reacts to the Make Noise calls. Dont know about others as last time i saw it it was on 4.7 or so.