No one ever said that talking computers were impossible. Yes: we did not know
how to do it, tech has since progressed. So how is this relevant ?
IBM introduced the 7770 and 7772 Audio Response Units in January 1964. The computer to which it was attached didn't synthesize voice. It sent codes to the ARU, which then read them from a drum. How many of us are old enough to remember the "ULrich 3 1212 Time Lady?"