The vocal-tract ‘‘potential function:’’ Many-to-one mappings and compensatory articulations in speech production

• Published in: The Journal of the Acoustical Society of America 2002-11, Vol.112 (5_Supplement), p.2417-2418
• Main Author: Forbes, Barbara J.
• Format: Article
• Language: English
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.4779891

A fully quantitative, mathematical framework for the analysis of compensatory articulations is described. It is shown that the physics of speech production is best described by a spatial ‘‘potential function,’’ which, unlike cylindrical n-tube approximations, accounts for dispersive wave phenomena in regions of rapidly varying cross section. It is demonstrated that many possible area functions, and hence articulatory configurations, correspond to a single potential function, and so it is claimed that the potential-function descriptor is a both more accurate and more compact basis for the scientific investigation of phonetic systems. This work demonstrates that a 27-vowel system may be simulated from just 8 binary, potential-function parameters. The acoustic correlates of the individual ‘‘bits’’ are discussed, and it is found that they characterize the main vowel classes in a transparent way. Transformations from high to mid, and from mid to low, vowels are obtained, along with those involving the tense–lax and round–unround dimensions. It is shown that vocal-tract area functions familiar from the literature can be deterministically recovered from the 8-bit strings, although many others are also possible. It is claimed that the potential-function vocal-tract model has uniquely abstract and compact properties, and is suitable for development as a full phonological representation.