LOGICAL TECHNIQUES FOR GLOTTAL SOURCE MEASUREMENTS.
AIR FORCE CAMBRIDGE RESEARCH LABS L G HANSCOM FIELD MASS
Pagination or Media Count:
This report describes a method of using a PDP-1 computer to reduce data from a very high speed motion picture that shows the human vocal cords during voicing and carries a visual representation of the electrical signal from a microphone held in front of the subject during the filming. The object is to get representations of the area of the glottis the opening between the vocal cords and the pressure amplitude of the acoustical signal as functions of time. The glottal area and the acoustical amplitude shown on each frame of the film are reduced to binary form and stored on magnetic tape, together with a set of coordinates representing the periphery of the glottis, all suitably identified. Each frame of the film constitutes a sample in time which is not uniform because of slight changes in camera speed. A second program interpolates the data to yield uniform samples in time, normalized and properly scaled for presentation on the computer scope. The two functions are also synchronized in time and punched out on paper tape. A third program displays the data from the paper tape as two curves, one above the other, which drift slowly across the scope face. New data is added and old data discarded so that the drift is forward in time. The drifting can be stopped and specific parts of either wave can be designated with the light pen for more detailed examination. Author