Bell Laboratories Computer Speech
To produce synthesized speech, the computer continuously produces nine control signals such as voice pitch, loudness, lip opening and other variables. The program uses 34 phonetic sounds (22 consonant and 12 vowel sounds). This historic recording was made by D.H. Van Lenten in 1962 as part of a series of experiments at Bell Laboratories to understand the nature of speech and hearing. It is even more remarkable considering that each of the nine controls for each phonetic sound was individually keypunched on a card and processed by a two-part program to produce a magnetic tape. This was then converted by a second program into an audio tape.