Reduction of Unstressed Prevocalic /u/ in English

This paper deals with the reduction of unstressed prevocalic /u/ and the appearance of /w/ which are observed in such words as ambiguity [ˌæm bǝ ˈgju: ǝ ti] - ambiguous [æm ˈbɪ gjǝ wǝs]. This phenomenon is recorded in Merriam-Webster Online Dictionary, Webster's Third New International Dictionary, Unabridged, and the draft revisions of Oxford English Dictionary Online. Since this phenomenon has not been studied in detail up to now, this paper aims 1) to collect the data related to the reduction of unstressed prevocalic /u/, 2) to classify them systematically, and 3) to explain the phenomenon in terms of Optimality Theory. In the course of analysis, Prevocalic Lengthening, which is crucial to the preservation of unstressed prevocalic /u/, is reinterpreted as one of the ways to prevent hiatus (annual /æ nju: ǝl/). /w/-insertion is another way to prevent hiatus (annual /æ njǝ wǝl/). In addition it is argued that prevocalic /u/ behaves differently from prevocalic /i/ due to the difference in the articulators involved.