Published online by Cambridge University Press: 06 February 2009
The Jakobsonian system of binary distinctive features is based on the premise that, as far as vowels are concerned, their articulation, and the resulting acoustic effects, are not distributed randomly over the available articulatory or acoustic space, but are organized into systems of binary contrasts, so that for example (in articulatory terms) a set of front vowels will be matched by a corresponding set of back vowels, a set of high vowels by a set of mid or low vowels, and so on. There will thus be a certain symmetry in the distribution of such vowels, either in their positions on a vowel quadrilateral, or in a similar schematic shape such as the five-vowel triangle.