You still have 3 option:
Pedestrian crossing - is defined in the standard iGO SpeedCam as 29 cat.
Sys.txt file for this category should be such a declaration:

[speedcam_category: 29]
activated_spoken_type = speech
activated_speech = "Pedestrian crossing"
warn_distances = "0: 100"
speedcam_maxdistance_from_road = 10
if you have a change in your way:

[speedcam_category: 29]
activated_spoken_type = none
activated_speech = ""
; warn_distances = "0: 100"
; speedcam_maxdistance_from_road = 10
And it will be quiet
If you do not have this provision - that put him.
Regards