Ha, this is amazing. Reminds me of movies using seemingly far-fetched premises at their time.
Sneakers - in the beginning when they're spying on Dr. Janek, the team can't see the entire password he types, but Whistler hears the missing keystroke.
And related to the original post, The Dark Knight has Batman using sonar from everyone's mobile phones to detect where the Joker's henchmen were and here we are with wifi routers (and potentially other 2.4 GHz devices).
They're all trying to figure out what the password is from the video, and Whistler is paying attention to what they're saying, which is that he has an answering service. And if he has an answering service, then the answering machine on his desk is hiding something in plain sight.
I don't believe that the scene you're thinking of happens. Whistler is pretty impressive, but even he can't hear the difference between keystrokes.
The other cool things that Whistler does are figure out where Martin was taken by the sounds that Martin remembers, and figure out what the various rooms in the building are via telescopic microphone ("Emergency exit stairwell." "How can you tell" "I can hear the emergency exit light batteries recharging") :D
I skimmed over the movie late last night and realised I completely misremembered the two scenes mentioned, and exaggerated Whistler's hearing abilities.
That wasn't far fetched at the time, apart from using a human to do the listening. There has been intense interest in audio processing for many years. This was to identify submarines; morse key operators; and to tell what's being typed on a type writer.
Sneakers - in the beginning when they're spying on Dr. Janek, the team can't see the entire password he types, but Whistler hears the missing keystroke.
And related to the original post, The Dark Knight has Batman using sonar from everyone's mobile phones to detect where the Joker's henchmen were and here we are with wifi routers (and potentially other 2.4 GHz devices).