I think the keypad is too simple of a device to make voice announcements. If Iris was really on top of their game, push notifications to mobile devices could roll out system sounds from your mobile device speakers, including door bell and door chime.
The one feature of my XFINITI system I can tell I'm going to miss is the voice announcement feature for zones. They had a (albeit small) handful of sounds you could select for when a zone opened or closed. When someone opened my front door I had it announce "FRONT DOOR OPEN". I had the option to select a closed sound too but I wasn't worried about that but the feature was nice. When my gun safe opened the sounds of a machine gun would sound. A pretty cool feature and was nice when I was across the house that I could tell which door/window/zone was opening. Hopefully this will come in a future upgrade!