text to speech

Hi there I have a blind customer who is not near me but deals with me
via phone. He has a nokia 6133 that "talks to him" announces the time
and things like that. Now I have seen some Nokias have the text to
speech option that this obviously does but how do you adjust it? tell
it what to say? volume etc, is there a setting in the phone I can
direct him to? He is great at navigating it est if I can give him a
menu setting ie menu 3-4-2 or whatever. He just wants to be able to
adjust it so he can have things repeated to him that aid him. thanks
in advance