Human speech ^ Recognition algorithms ^ Response device

Today, many different types of algorithms can be used to interpret human speech. An important feature of many of these algorithms is that they can learn to recog­nise the sounds of different voices and accents. In ideal conditions many algorithms can recognise more than 90% of speech. When situations are less than ideal—for example, in a noisy environment or when a speaker has an unusual dialect—the recognition might be severely impeded. In a control room situation, one can expect the use of a rather limited vocabulary, for example, in emergency situations. With a limited vocabulary the speech algorithm can be developed to recognise many differ­ent accents, even when the background environment is noisy and disruptive.

A speech generation system is the mirror image of a recognition system. It con­sists of a device to generate messages in the form of symbol strings, a speech gen­eration algorithm to convert the symbol strings to an acoustic imitation of human speech, and a human listener. A speech generation system operates within the con­text of the user’s working environment: