Date of Award

Fall 1974

Document Type

Thesis - Restricted

Degree Name

Master of Science (MS)


Electrical and Computer Engineering

First Advisor

Niederjohn, Russell J.

Second Advisor

Heinen, James A.

Third Advisor

Wu, S. H.


A study of the zero-crossing analysis techniques which have been applied to automatic speech recognition is presented. Their mathematical interrelations and interpretations are reviewed. A study of the application of these to sine-waves of various frequencies under noise-free and noisy signal conditions made. Ten English vowels with six repetitions of each, by the same talker, recorded on a magnetic tape are chosen as the basic source of speech sounds for this thesis. One of the methods, namely the method h, is found to have desirable frequency discrimination characteristics. The vowels "formula" cannot be separately recognized on the basis of their second formant frequencies because these frequencies are close to each other. The method h results in least 6 and is thus less vulnerable to noise. In fact, it can sustain 5 dB more noise than the other methods.



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