What is a Computer Microphone?

It is quite easy to convert the spoken word to a digital signal for computer input. The microphone converts audio signals to electrical waves and these can be converted by electronic circuitry in the computer to digital from. What is difficult is the recognition by the computer, of the signal, so that it can be handle it in the same way as if it had been typed. Highly sophisticated speech-recognition software is required to be able to match the sound uttered by the user with a vocabulary of sound signals stored in the computer and to display the words on the screen as though they had been entered at the keyboard.

The development of workable speech-recognition system for the English language has been major goal of many researchers for a number of years. Recently, commercial systems have started to emerge. One major problem is the many inconsistencies between the written and spoken words in English. Japanese, in contrast, is phonetically very precise and so speech-recognition system for those languages were relatively easy to develop and have been used for some time.

A second problem is the fact that there can be wide variations between the speech patterns of one individual and another. To cope with this, the system has to be trained to recognize the user’s particular speech. Most systems require him/her to read a passage containing all the words stored in the computer’s vocabulary on disk, so that it is able to match what is spoken with what is stored. In this way it constructs speech templates for the user, which it store for use in all subsequent dictation sessions.

Speech-recognition system in the past have suffered form either having too limited a vocabulary to be of much use or else, in the case of large vocabulary system, taking far too long to match what was spoken with what was stored in the computer. Recent increases in computer power have greatly speeded things up and voice system on personal computers have now appeared.