Speech recognition systems fall into four categories,
depending on whether they are speaker-dependent or
independent of speaker population and on whether they are
capable of recognizing continuous speech or only isolated
words.
A study was made of most methods used in speech recognition
to date. Four speech recognition techniques for
speaker-dependent isolated word applications were then
implemented in software on an IBM PC with a minimum of
interfacing hardware. These techniques made use of short-time
energy and zero-crossing rates, autocorrelation
coefficients, linear predictor coefficients and cepstral
coefficients. A comparison of their relative performances
was made using four test vocabularies that were 10, 30,
60 and 120 words in size. These consisted of 10 digits,
30 and 60 computer terms and lastly 120 airline reservation
terms.
The performance of any speech recognition system is
affected by a number of parameters. The effects of frame
length, pre-emphasis, window functions, dynamic time
warping and the filter order were also studied experimentally. / Thesis (M.Sc.-Electronic Engineering)-University of Natal, 1990.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/6896 |
| Date | January 1990 |
| Creators | Pitchers, Richard Charles. |
| Contributors | Broadhurst, Anthony D. |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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