<<The sounds of the airport are also played over speakers, to make this virtual world more realistic - potentially noisier, in fact, than some insulated control rooms - after trials showed it helped controllers. “It sounds a bit silly pumping noise into a control room but it’s something they need to do the job,” Anderson added.>>
Really? What about major airfields where the Tower maybe some distance from the runway? I don't recall any extraneous noises at Heathrow Tower. If there were they were probably drowned out by internal noises.