Personally, I wonder who thought a telephone ringing tone was a brilliant
idea for a floor passing chime? Elevators with computer processors can
better monitor the elevator (how many times it went up/down, how many times
it went to floor 3 for example). Similar reasons were the big selling
points of the original OTIS Elevonic 401 system.
There are plenty of reasons why: 1. The fixtures are broken 2. The building
owner doesn't like the fixtures 3. The pump is too noisy and/or power hungry