The Voder – Bell Labs (1939)

Demonstration of the first electronic speech synthesizer.

Included in this demo:

1. The voders capability to say words with expression.

2. Voice pitch changes.

3. The voder singing.

4. Speaking foreign languages.

5. Reciting the alphabet.

You can see it sort-of in use at the start of this AT&T commercial:

https://www.youtube.com/watch?v=IEp6ca9Ppks