This wonderful relic from the dawn of speech synthesis is a 2-minute recording from Bell Laboratories, first published in 1962, showcasing the work of John L. Kelly and Louis J. Gerstman for the Visual and Acoustics Research Department.  I acquired this 45 RPM soundsheet in 1966, in the 9th grade, when I began working on a speech synthesis system of my own. (I finally made it to the International Science Fair in 1969 with my “acoustic analog of the vocal tract,” which even had a voice-change problem.)  I slurped this from a USB turntable in 2008, conjured an MP3, then sold the soundsheet on eBay.

The Bell Labs speech synthesis soundsheet from the early sixties