Spectral envelopes and perceptual target zones for consonants and vowels: Preliminary estimates

Abstract

Preliminary estimates of the sizes, shapes, and locations of perceptual target zones (PTZ) of ten vowels, six dipthongs, a twenty‐nine consonants have been made. The PTZ's are defined as enclosed volumes in the space x = log(PF3/PF2), y = log(PF1/PR), and z = log(PF2/PF1), where PR is the perceptual reference in Hertz and PF1, PF2, and PF3 are the center frequencies of the perceptual formants. The perceptual formants are estimated from spectral envelopes as guided by rules for distinguishing burst‐friction spectra and glottal‐source spectra and for naming and numbering formants based on their logarithmic relations to the value of the reference. The estimation of PTZ's will be illustrated for at least one allophone from each of the following classes: vowels, diphthongs, approximates, nasals, voiceless fricatives, and voiced fricatives. These preliminary estimates indicate that PTZ's: (1) are large, thus encompassing a considerable range of spectral variants as might be associated with coarticulatory effects and articulatory style; (2) have irregularly shaped, abutting boundaries; and (3) for the most part, exhibit little overlap. [NINCDS grant R0 I‐NS21994‐01.]