Vowel recognition: Formants, spectral peaks, and spectral shape

Abstract

The purpose of this presentation will be to review some recent research on the acoustic characteristics of American English vowels, and to discuss some issues related to the auditory mechanisms underlying vowel recognition. Evidence from studies using traditional formant frequency representations will be reviewed to address issues such as talker normalization and the role of dynamic features in vowel identification. A long-standing debate in phonetic perception theory concerning whether phonetic quality is controlled by formant frequencies or the overall shape of the spectrum will also be addressed. While formant theory has tended to dominate much of vowel perception research, some compelling arguments have been leveled against formant representations; however, there are also some very important problems with whole-spectrum representations. A new method of representing speech will be described which is believed to address some of the limitations of both formants and overall spectral shape. The masked peak representation (MPR) was designed to: (1) show maximal sensitivity to spectral peaks, (2) show minimal sensitivity to spectral shape details in nonpeak regions, and (3) avoid explicit formant tracking. Preliminary results will be described from an experiment in which listeners are asked to identify /hVd/ utterances that were synthesized from MPR spectra.