Helium Speech Translation Using Homomorphic Deconvolution
R. Frank Quick · The Journal of the Acoustical Society of America · 1970
Previous research by Oppenheim has established the applicability of homomorphic deconvolution to speech analysis-synthesis systems. The present research is an application of homomorphic methods to the problem of correcting divers' speech in pressurized helium-oxygen atmospheres. The vocal tract impulse response of such speech was extracted by the homomorphic deconvolution technique, and its frequency components were moved downward in frequency according to correction formulas given in a study by Gerstman. Both linear and nonlinear frequency corrections were used. Speech samples taken at 800 ft pressure depth in a 96% helium, 4% oxygen atmosphere were processed in this way, using a digital simulation of Oppenheim's analysis-synthesis system. Results indicate considerable promise for the technique as a tool for further study of helium speech, and perhaps as a future on-line translation method. [This work was done at the Air Force Cambridge Research Laboratories while the author was enrolled in the Electrical Engineering Department cooperative program.]