The PIVOT parser

Similarly to lahguage aquisition, language processing faces a strong input-datadeficiency problem. When we speak we alter a great deal in the idealised phonetic and phonological representations. We delete whole phonemes, we radically change allophones, we shift stresses, we break up intonational patterns, we insert paus es in the most unexpected places, etc. If to such crippled phonological strings we add all background noise which does not help comprehension either, it is difficult to imagine how the parser is supposed to recognise anything at all. However, even in the most difficult circumstances (foreign accent, loud environment, drunkenness, etc.) we do comprehend speech quickly and efficiently. There must be then some signals in the phonetic string which are particularly easy to grasp and to process. We call these signals PIVOTS and parsers working with these signals we call PIVOT PARSERS. THE PHONOLOGICAL PIVOT What are then the pivots in the phonetic string? Dogil (1987) argues that at each level of prosodic organization there exist prototypical, unmarked structures which not only manifest themselves in patterns of all natural languages but are also clearly visible in the areas of external evidence such as language acquisition, language loss, and language change. Here we will argue that that these ideal prosodic types play an important role in language processing. At the lowest prosodic level the level of the syllable such an ideal type is constituted by a CV syllable. That is, the prototypical, unmarked syllable consists of a single consonant followed by a vowel. There is plenty of evidence for this prototype. For example: there is no language which does not have CV syllables, but there are many languages which have only CV syllables. phonological rules which obliterate syllabic structure usually spare CV syllables. CV syllables are acquired first in the process of language acquisition. CV syllables are preserved even in the most severe forms of motor aphasia. historical syllabic restructuring rules tend towards the creation of CV syllables. when subjects are asked to synchronise clicks with syllables it turns out that the clicks are aligned at a point,called the P-CENTRE (or 'perceptual centre'), which is close to the CV transitions of the syllable. listeners can classify stops by place better than chance when they are given onlythe first 10-46 msec. of CV syllables. * Universität Bielefeld, Fakultät für Linguistik und Literaturwissenschaft.