Radio Rex- Speech recognition has a long and spotty history in the toy industry. Radio Rex was the first commercial toy to respond to voice commands. Produced in 1922 by the Elmwood Button Co., Radio Rex predates computers by more than 20 years. Rex is a brown bulldog made of celluloid and metal that responds to its name by leaping out of its house. The dog is controlled by a spring that is held in check by an electromagnet. The electromagnet is sensitive to sound patterns containing acoustic energy around 500 Hz, such as the vowel in "Rex." The acoustic trigger interrupts the current to the electromagnet allowing the spring to propel Rex out of its house.

JG- if you had that metal dohickey poking at your hind end, you would probably look as bad in the face!
Curt

That is one ugly mutt!!!!

Hi John,
That's clever, but the crudest possible voice recognition. I study sound spectrograms all the time in my phonetics course, and it is true that the first formant in the vowel [e] is at about 500 hz, but only in the adult male voice, so Rex would not respond to women or children unless they used a different vowel, like [i] or [I], or even [u] or [U]. They would have to call him "Reeks" or "Riks" or "Rooks" or "Ruks" in order to get the first formant low enough. I bet you have to say it really loud, too.