Chapter 2. Overview of Spoken Language Technology


To make effective design decisions, you need to understand the strengths, weaknesses, and possibilities of the underlying technology. This chapter introduces speech technology at the level of understanding required by VUI designers and discusses how this understanding should come into play when you make design decisions.

Even though speech recognition technology is only now becoming commonplace, it has been with us for almost a century. The first success story was actually a children's toy, produced around 1911, called Radio Rex (pictured on the book cover). This toy was a small celluloid dog sitting in a tin-roofed doghouse. Inside the doghouse, an electromagnet held a spring-loaded lever. There was a metal bridge in the circuit that supplied power to the electromagnet. The bridge was tuned to have a resonance around 500 cycles per second, which coincides with a resonance in the vowel sound for the word "Rex." When the dog's name was called, the energy in the vowel caused the bridge to vibrate, breaking the circuit. When the magnet shut off, the spring-loaded lever was released and sent the dog flying out of the house in response to his owner's call.

Rex was a commercial success despite its simplicity and one-word vocabulary. (That was lucky, given that more capable technology was not available for another 40 years!) Today's commercial systems require a bit more sophistication, as described in this chapter.



Voice User Interface Design 2004
Voice User Interface Design 2004
ISBN: 321185765
EAN: N/A
Year: 2005
Pages: 117

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