Methods for Integrating Phonetic and Phonological Knowledge in Speech Inversion

Exploiting the information about the vocal tract shape that produced the speech has been appealing to speech researchers and scientists for a long period of time. Experimental studies that included the articulatory information from physiological measurements supported the idea that this information could be useful in a number of areas of speech science and technology. However, the estimation of articulatory trajectories from the speech acoustic signal is known as a difficult and ill-posed problem. Among the relatively recent methods proposed to solve this problem are those trying to integrate linguistic knowledge in the form of phonetic or phonological constraints. This paper reviews and discusses upon methods for applying phonetic and phonological constraints to provide unique solutions to the acoustic-to-articulatory inversion. Key-Words: speech inversion, acoustic-to-articulatory mapping, vocal-tract estimation, phonetics, phonology