Minimising the storage
By a theory combining the work of Diana Archangeli in the 1980s, that of Carole Paradis and Jean-Francois Prunet and contributors in the 1990s, summarised by Michael Kenstowicz (1995), further developed in Nunes (2002), multiple phenomena are best explained by assuming that what the brain stores of the sound structure of words is reduced to barest minimum. Rather than storing every detail that defines the actual pronunciation, the brain stores something like a highly compressed version, consisting of single features or even just a bare ‘slot’ for a consonant or vowel. For instance, in the case of English, if there are three consonants before a vowel, the first has to be S, the second has to be K or P, the third has to R or W after K, as in scream or square, or R or L after P, as in spring or splash. S in these cases need be represented only by a one segment slot before two others before the vowel.
Archangeli (1984 and 1988) calls her version of this approach ‘Radical underspecification’.
Prunet and Paradis (1991) just address the special status of those consonants articulated with just the tongue tip against the fleshy ridge ,just behind the upper front teeth, in English T, D, N, S and Z.
Kenstowicz (1995) calls these approaches ‘extrinsic’ and ‘intrinsic’ underspecification.
On the strength of the patterning of speech errors in English, Nunes (2002) argues for a combination of extrinsic and intrinsic underspecification. This minimises storage, but requires that every phoneme has to be derived in order to be pronounced. There is an obvious trade-off in one direction or the other. By the proposal is here, the issue is not one of abstractly weighing up the empirical or theoretical advantages either way, but considering the logically possible sequencing of evolution. Underspecification is not an advantageous economy or disadvantageous penalty but just a consequence of the first steps towards modern speech, from which there was no going back.
Ken Stevens proposes that some aspects of speech have the special role of ‘enhancing’ contrasts, like the rounding of the lips in the case of vowels articulated with the tongue at the back of the mouth, like those in woo and war.