Check the audio panel. A lot of birds I've seen have it tied into the ADF IDENT function on the audio panel. If that's off you won't hear it, if the IDENT is on you will.
This is of course if you don't have a RMI or ADF in the airplane.
voice option, as noted above, is part of the GTX-330 not the GNS-430. Get your mechanic to start it up in the maintenance mode and you can adjust the volume and mail/female voice among other things.
Don't let your mechanic mess with stuff you don't know anything about, though.![]()