At the 1939 World's Fair a machine called a Voder was shown . A girl stroked its keys and it emitted recognisable speech. No human vocal cords entered into the procedure at any point; the keys simply combined some electronically produced vibrations and passed these on to a loud-speaker." ("As We May Think" by Vannevar Bush, 1945. )

mr homer dudley, a research physicist at Bell Labs, built his "voder" 1939 for speech analysis and resynthesis.

the objective of early research on speech synthesis was to test whether the synthesizer design is capable of high-quality imitations of human voices.

but there are also some early mechanical examples: "Wolfgang von Kempelen introduced his "Acoustic-Mechanical Speech Machine", which was able to produce single sounds and some sound combinations (Klatt 1987, Schroeder 1993). In fact, Kempelen started his work before Kratzenstein, in 1769, and after over 20 years of research he also published a book in which he described his studies on human speech production and the experiments with his speaking machine.