Hello Friend soul2sou - you have 2 choices:
1. Through the interface iGO - look at the screen in this post -> [Only registered and activated users can see links. ] - enter the Options Settings / Sound and Warnings / Alert Point Settings / Alert Types / Pedestrian crossing - and here you are with a click Warning Type - Audio and Visual or Disabled or Visual. Sometimes, however, this way (I do not know why) fails.
2. The method of radical and reliable - you iGO / content / voice / i18 / dictionary.voice - are in the line -
Pedestrians = "Pedestres" (this is probably at you)
You make changes to:
Pedestrians = "" and you have a blissful silence forever!
You can - if you want to insert any text, eg>
Pedestrians = "Vire limpadores de pára person!" - But it is your choice.
Leave the editing to confirm that - ask to save, leave the record confirming Lang.zip file changes and you're done.
Remember that you make on your computer editing and not in the device and without unzip the file (zipped file editing)
Regards wojpen