Off the cuff: CHapp, CHappy, Chat-Chat, Chattre or Chatte[French], Talk-Talk(TT), Talk-Back, Back-Talk, Bark, Bark-Back(BB) & BB King (its upgrade), Begorrah!(

Off the cuff: CHapp, CHappy, Chat-Chat, Chattre or Chatte[French], Talk-Talk(TT), Talk-Back, Back-Talk, Bark, Bark-Back(BB) & BB King (its upgrade), Begorrah!(just an Irish word I like). Best is something that sticks to memory instantly.