The Voice English/Spanish Translator was born in a hallway in 1989 at AT&T Bell Labs' Murray Hill facility. Four Bell Labs engineers -- F. Pereira, M. Riley, D. Roe, and R. Sproat -- who had been working on speech recognition and synthesis projects, struck up a conversation with two visiting researchers from Telefonica Investigacion y Desarollo, the Spanish equivalent of AT&T Bell Labs. The four quickly realized that their research provided all the components needed to create a real-time language translator.

Three years later, the VEST gave its first public demonstration. It recognized roughly 450 words in over a billion sentence combinations. It would first determine which language was being spoken, break down the sentence into its grammatical components, and translate it as text — all in less than a second. It also had a language compiler, which collected grammar rules every time it performed a translation. This helped the VEST to provide ever-faster and more accurate translations every time it was used.