Man machine interaction by voice: Developments in speech technology

Abstract

Man-machine communication by voice is no longer a far-fetched notion Indeed the ' talking and listening' machine has already left the frontiers of science fiction fantasv. This paper outlines the limitations of existing means of commumcation with computers and the background to developments in voice input/output technology. Within the area of man-machine communication by voice there are three main avenues of research: speech synthesis (voice output), speaker recognition (identification and verification), and speech recognition (voice input). The technology common to these developments is speech encoding-digital representation of voice signals for processing by a computer. Techmques of speech encoding and speech synthesis are relatively well developed Speech recognition technology, however, is still in its infancy The recogrution task is complicated chiefly by the fact that characteristics of the speech signal differ from person to person, and even in the speech of one individual on different occasions. Because of this, it is more practical to divide speech recognition into four smaller categories, according to whether the systems are speaker-dependent or independent and recognized isolated words or continuous speech. Most of the commercially available systems are speaker-dependent/Isolated word systems. Up to now such systems have been hamstrung by poor recognition accuracy, insufficient vocabulary size-typically in the region of 100 to 200 words-and high implementation cost. Fortunatelv, the situation is improving rapidly and, indeed, claims for recently marketed systems sound most impressive-accurate recognition of up to 1000 words or more. The ultimate goal in speech recognition is speaker-independent/continuous speech systems which, although technologically feasible at the present time, may hot be available commercially for some time yet. And finally, speaker recogmtion can be regarded as a special case of speech recognition: nevertheless it is different in terms of its practical applications. . Existing products are particularly swtable for ' hands-busy. eyes-busy' operations and indeed they are used in several manufacturing applications and also as aids to the disabled They have also made a significant impact in voice store-andforward applications. Those who are planning to use Voice I/O systems have a wide range of technological options from which to choose These include complete turn-key systems, penpheral attachments to one's own computer, plug-in boards, chips and even software packages. However most potential users are taking a cautious approach because of technological and economic uncertainties in the speech product market. There is no reliable guide for users to assess the standards of performance of individual systems. There are also several other problems still to be resolved before speech technology products become widely applicable. These range from computation and technical problems-phonetic, semantic and syntactical-to user acceptance/interface of the end-products.Part II (following paper in t...

Design and evaluation of a speech interface for remote database searching

“…However, Blaise is a more complex system and there m a wuder variety of voice prompts and none of the users in our experiments got to the position where these prompts were so familiar to them that they were becoming irksome. It may be that after a user had been using the voice interface to Blaise for a much longer period, [12][13][14][15][16][17][18][19][20][21][22][23][24] hours, rather than 3-6 hours, they would find the repetition of voice prompts irritable and switch the voice output off as users of MicroBIItD tend to do. Another reason could well be that MicroBIRD required repeated confirmation from the user as a safeguard against misrecognition of spoken entries, however the Table 3 Comparison of performance of male and female subjects showing that our eight female subjects were vlightlv faster with a kevboard and slower with «ce mput than the male subjects.…”

“…Traditionally the man-machine interface for these systems has been the keyboard and screen. We believe that a speech interface has several potential advantages over the existing &dquo;speechless&dquo; method [11][12][13]. Speech is the most natural form of communication and should therefore speed up the search process.…”

Speech technology developments in Europe

“…Speech technology consists of three developments: Speech synthesis (output), speech recognition (voice input), and speaker recognition (verification/identification) (Philip & Young, 1987). Speech synthesis is a fairly well established technology and it involves the automatic conversion of text to speech.…”

Man-machine interaction by voice: Developments in speech technology. Part II: General applications, and potential applications in Libraries and Information Services

“…In Part I, we have outlined the major developments in speech technology and the problems that must be overcome before such systems become widely applicable [23]. The object of this paper is to discuss the existing and potential applications of this evolving technology.…”