Phonetic Universals in Vowel Systems

From an evolutionary point of view, it does not appear unnatural to assume that language form is forged by the sociobiological conditions of its use. Thus spoken language tends to evolve sound systems and grammars that can be explained, at least in part, with reference to the fact that it is spoken. It uses the vocal-auditory channel and ought therefore to exhibit adaptations to the developmental and adult mechanisms of speech production and speech perception. This point of view implies furthermore that the structuring of sign language should similarly reflect the constraints of its transmission medium, the gestural-visual channel, and that comparative study of speech and sign would be capable of offering important insights into the mechanisms of language (Bellugi & Studdert-Kennedy 1980). The present chapter is a contribution to the paradigm aiming at the phonetic explanation of language universals (Ohala, forthcoming), and thus it exemplifies the functional perspective described above. It investigates the extent to which certain universal aspects of vowel systems can be said to be consequences of similarly universal properties of speech production, human hearing, and speech perception.