Time Noise and Silence

"I lived and studied under the path (where the banking occurs) of the Rwy 13 Approach back then, it was noisy enough to interrupt our teacher every 3 minutes for say 20 seconds.  And there was "always" a plane departing in between the 3 minutes interval, although not as noisy as it flew over towards the sea. I also noticed that, the local players, namely Cathay Pacific, usually made the approach path a bit wider and a bit more towards the hill so they can have a longer final and a shallower angle of turn, then the published procedure. Also rememered I can occasionally feel and hear the wake turbulance even from a meduim weight aircraft, from my school playing ground in the good old days...Long live Kai Tak."
Accessed March 15, 2010, http://www.liveatc.net/forums/listener-forum/kai-tak-old-hong-kong-airport/5/?wap2.


Based on the above account,
In a typical elementary school day of 6 hours (360 minutes), the teacher stopped a total of 40 minutes.
In one school week of 5 days, the teacher stopped a total of 200 minutes or 3.33 hours.
In one month of 21 school days (assuming no public holidays), the teacher stopped for a total of 70 hours.