Perceptual distances between vowels located in a limited phonetic space
Diane Kewley-Port, Bishnu Saroop Atal · The Journal of the Acoustical Society of America · 1983
Knowledge of objective measures of perceptual differences between vowel spectra is of crucial importance in the design of speech coders. Toward this goal we have developed procedures for obtaining a multidimensional representation of the perceptual space over a limited vowel region. First, natural sounding vowel stimuli were synthesized using an lpc formant synthesizer. Starting with formants measured from a male talker's vowels, stimuli were generated by varying F1 and F2 in small increments. Listeners judged the dissimilarities between all pairs of vowels several times. These perceptual differences were mapped into distances between the vowels in an n-dimensional metric space using multidimensional scaling. In the first study, 11 steady-state stimuli were synthesized in the region of /i/ and /I/. Although the physical stimulus space had only two dimensions (F1 × F2), the resulting perceptual space had at least three dimensions. In this paper, perceptual spaces for stimuli located in other vowel regions, as well as for vowels embedded in a consonantal context, will be compared. Finally, we will discuss a measure of the difference between these perceptual spaces and their physical stimulus spaces calculated from nonlinear regression techniques.