Fricative Production by a Dynamic Analog Synthesizer

Abstract

Two series of formal listening tests were conducted with fricative consonants generated by a dynamic analog of the vocal tract. The consonants were generated using a fricative configuration consisting of a uniform tube with a single constriction and were presented in CV context, always with the vowel /ɑ/. The variables studied in the first test series were the place and degree of constriction and the position of noise excitation relative to the constriction. Listeners were required to make one of six fricative responses in forced and nonforced tests. Responses of /s,∫,f/ better than 95% were obtained for some stimuli. The second series of tests was made to determine how closely the temporal relations between articulatory change and buzz and noise excitation need to be specified. Stimuli were presented in pairs and subjects were asked to vote for the more “natural” stimulus in each pair. A supplementary identification test showed a sharp change of response from voiceless to voiced fricative as buzz excitation was initiated at progressively earlier times. [This work was supported in part by the U. S. Army (Signal Corps), the U. S. Air Force (Office of Scientific Research, Air Research and Development Command), and the U. S. Navy (Office of Naval Research) and in part by Air Force Cambridge Research Center Contract AF 19(604)-2061.]