Noise contours for the Bombardier CS100 and the Porter Airlines expected order

Noise contours for the Bombardier CS100 and the Porter Airlines expected order:
from Leeham News and Comment by leehamnet
The news that Canada’s Porter Airlines is the Unidentified North American customer that signed a Letter of Intent for up to 30 Bombardier CSeries for use at Toronto City Airport sparked a lot of noise (pun intended).
Late yesterday The Wall Street Journal reported that Porter will announce its order tomorrow.
Key to the order is the fact that BBD and engine provider Pratt & Whitney promise a low noise footprint and just 70 decibels approaching the airport. Toronto City Airport is a highly noise-sensitive airport.
As yesterday’s post about all this noted, Porter and the OEMs will argue the CS100 is no louder than the Bombardier Q400 now serving the airport. This leads to a small noise contour, or foot print, as illustrated in this BBD chart:


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The Ft. Lauderdale airport (Broward County) has this set of Airport Noise Contour descriptions.
But what does this mean to the average ear? There are several tables on the Internet that give examples. AirInsight has a chart here that equates specific aircraft to common noises. This chart below also gives some examples of dBA levels.

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Noise chart Source
The Porter order will almost certainly prompt a local political row, according to the Financial Post’s aerospace reporter, as suggested in his own Tweets that we reproduced last night.