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Acoustic Characteristics Of Vowels Produced By Men, Women And Children, Laura Arlene Getty

Masters Theses

This investigation was a replication and extension of Peterson and Barney’s (1952) research on the acoustics and perception of vowels. This study explored the acoustic characteristics of 12 vowels produced by 50 men, 50 women and 41 children. Speech samples were tape recorded as subjects read lists of words and isolated vowels. Speech samples were digitized. Speech waveforms, spectrograms and formant frequencies were examined and measured.

The average formant frequency values were similar but not identical to the values reported by Peterson and Barney (1952). The largest discrepancy between the two studies was the degree of overlap among vowel categories, …

Analogical Reasoning Of Elderly Adults Using Three Modalities: Words, Pictures, And Figures, Judy L. Rau

Masters Theses

This study examined the analogical processing skills of elderly adults. Forty-seven subjects (ages 65-90) completed analogy tasks presented in three modalities: words, pictures, and geometric figures (90 total). The subjects for this study were elderly adults living independently in a federally subsidized apartment building. The subjects used in this study possessed characteristics similar to the "typical" American adult. Results indicated that performance does not vary significantly with age in the word and picture modalities. Significant (p < .05) negative relationships were found between performance on the geometric figure analogies and increased age and between overall performance and increased age. Significant (p < .05) positive relationships were found between education and performance on each of the three modalities as well as between education and overall performance.

Perceptual Effects Of Perturbation And Additive Noise, Richard E. Nero

Masters Theses

This study investigated the perceptual effects of varying glottal waveshape perturbation, duty cycle perturbation, jitter, signal-to-noise ratio perturbation, and shimmer at three levels of perceived magnitude (high, medium, and low). Voice signals were synthesized using a modified version of Klatt's (1980) formant synthesizer. Listeners rated signal dysphonia using an A-B dissimilarity procedure. Multidimensional scaling analysis suggested that signals judged low in magnitude of dysphonia were perceived to be most similar. Medium-level and high-level magnitude signals were judged to be respectively less similar. Signals varying in duty cycle and fundamental frequency perturbation were perceived to be very similar while those signals …