Extraction and Portrayal of Pitch in Speech Sounds
Otto O. Gruenz, L. O. Schott · The Journal of the Acoustical Society of America · 1949
An improved method for automatically extracting the pitch information of speech sounds has been devised. It employs a combination of gain control, double detection, voiced sound selection, unvoiced sound exclusion, and a means for counting the fundamental vibrations in the voiced sound intervals. Reliable indications of pitch have been obtained over a range corresponding to frequencies from 100 to 600 cycles for a wide variety of voices. Several visual portrayal means that have been used to show pitch changes are described. One means involves a display of colored light which changes from purple through amber to blue as the pitch increases. Another is in graphical form employing an array of staff-like lines whose spacings widen or narrow in contour fashion to show how the pitch varies with time, permitting a detailed study of the changes.