Speech Synthesis, Bell System Science Experiment No. 3

This is an electronic vowel sound synthesizer. The 133 page book, Speech Synthesis, An Experiment in Electronic Speech Production, (c) 1963, covers human speech production and it's synthesis. It was written by Cecil H. Coker, Peter B. Denes, and Elliot N. Penson of Bell Telephone Laboratories.

The project has 6 transistors, and 3 ferrite core coils. It is object of historical interest from the glory days of Bell Labs. It makes vowel sounds, (a,e,i,o,u) when correct value capacitors are inserted in the 3 Formant Generators. It requires 3 different input voltages from 3 batteries in series. I built this project in 1968.

In the late 1950's and early 1960's, small solid state AM radios were advertised by the number of transistors they had. Six transistors was a lot considering that radios usually had between 3 and 12 transistors. The transistor was the most important seed invention of the century.