Here is the referenced article about Pedro the Voder, an early speech synthesizer.
Grandmother of Pedro the Voder
If a certain Professor Faber could listen to “Pedro the Voder,” the amazing new machine that produces artificial speech with vacuum tubes (P.S.M., Apr. ’39, p. 72), he would see the realization of a dream that haunted him a lifetime. For forty years this Austrian experimenter labored to create a machine that could talk. His nearest approach to it, by 1870, was the remarkable contrivance above.