The goal of the proposed research is to develop and evaluate a new voice source model based on physiological observations of the vocal folds of 30 adult speakers. Shortcomings of existing source models can be in part attributed to the way in which they were developed: based on limited data from a few speakers, without direct physiological observations, and without perceptual validation. A larger dataset would help in not only developing a source model that could account for a range of voice qualities within and across speakers, but also result in an understanding of how and which model parameter(s) are speaker and/or gender specific. Model development will consider the perceptual effects of the model's parameters from the earliest stages. A better source model might also improve the performance of speech processing algorithms such as text-to-speech synthesis (TTS). Typically in the development of such algorithms, the emphasis has been on acoustic features related to the speech spectral envelope. The acoustics of the voice source, on the other hand, have received less attention. The proposed work involves: 1) recording high-speed images of vocal fold vibrations with simultaneous audio recordings from 15 male and 15 female speakers, 2) extracting glottal area functions from the images to parameterize a new voice source model, 3) performing perception experiments to uncover which model parameters are perceptually salient, and 4) using the new voice source model in TTS. The project's interdisciplinary team (with expertise in modeling, synthesis, recognition, phonetics, and psycholinguistics) is uniquely qualified to conduct this transformative research.
