The Representation of Vowels and Their Movements
Ralph K. Potter, Gordon E. Peterson · The Journal of the Acoustical Society of America · 1948
It is shown that movement of the major resonances in the voiced sounds of speech may be represented by traces in a three-dimensional graph. Apparently a great deal can be learned about speech through investigation of such traces, and they suggest a new method for vowel designation that is particularly adaptable to quantitative analysis.