In 1953, JCR Lickleader, a computer scientist at Harvard, invented the watermelon box, probably the first speech-understanding machine. It consisted of a microphone connected to four circuit boards. Each circuit board recognized a single vowel sound. A red light on the top of the box lit up whenever anyone within earshot said the word "watermelon."
People with a moderate level of education use about 9,500 words in everyday conversation. By designing 9,499 more word recognition boxes, it was thought a machine could be made to understand spoken language. Unfortunately, the watermelon box was highly unreliable as it depended on the unusually distinctive sequence of vowel sounds in the word "watermelon."
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