They have been shown to work at other airports around the world. Lufthansa, in Germany, voluntarily modified their aircraft and were one of the first airlines to do so. Gatwick has introduced a financial penalty if airlines operate a modified aircraft.
It has to, again, be finding the right solution for Canada. I still stand by the recommendation that there should be action to persuade carriers to modify the A320. It is a simple refit or modification to the aircraft that can make a significant impact on noise.