I've looked and I am not aware that this can be done. My guess is that the tone is a positive feedback so we know the phone is actually dialing, designers figured we would always want it. But there should be a way to quiet it if so desired. Perhaps someone else knows if it can be done.
Well, temporary switching to the "Vibrate only" profile would do the trick, but I guess that's not suitable for a permanent solution... Posted via BlackBerryForums.com Mobile
That question has been asked many times here. A search turned up several threads asking the same question and all of the answers are the same. There currently isn't a way to turn off keypad tones when dialing.