John Hogden Anders Lofquist Vincent Gracco Kiyoshi Oshima Philip Rubin Elliot Saltzman
Haskins Labs., 270 Crown St., New Haven, CT 06511
To examine the mapping from acoustics to articulation, simultaneous articulatory and acoustic measurements were made of 90 vowel-to-vowel transitions produced by a Swedish speaker. Articulator positions were measured using an electromagnetic midsagittal articulometer that tracked seven receiver coils placed on the lips, jaw, and tongue. The vocal tract transfer function associated with each articulator position was estimated using cepstral analysis on short windows (25.6 ms) of the acoustic signal. The transfer functions were then vector quantized, giving each articulator configuration a corresponding vector quantization code. Given an acoustic signal and its corresponding vector quantization code (code 1 for example), an estimate of the position of any coil during the production of a speech signal can be made by averaging all the positions the coil assumed during the production of sounds labeled with vector quantization code 1. This produces a codebook that allows articulator positions to be estimated from acoustic signals. On a data set not used for training, correlations between estimated and actual receiver coil positions vary strongly with the place of attachment, but correlations above 0.9 are common for coils on the tongue. [Work supported by NIH.]