Interesting Stop Request sound on Calgary Transit MCI Classic

Surprisingly, 1991 MCI TC40-102N Classic #5047 has a newer-style electronic Stop Request sound (like those on the New Flyer D40LF's and Novabus LFS's), instead of the bell that all the other Calgary Transit MCI Classics have. This video was taken on Route 14 Cranston/Bridlewood, at Bridlewood Avenue/Bridleridge Way (Bus Stop 9600).
Specs:
Detroit Diesel 6V92TA
Allison VR731