Phonological Neighborhood Density in the Trevor Corpus: Perception and Production Factors in Lexical Acquisition

Abstract

UC Berkeley Phonology Lab Annual Report (2010) Phonological Neighborhood Density in the Trevor Corpus: Perception and Production Factors in Lexical Acquisition Melinda Woodley University of California, Berkeley Since at least the 1980's, phonological neighborhood density (henceforth PND) has been recognized as an important factor in speech processing (e.g. Goldinger, Luce, & Pisoni, 1989). One of the reasons it has provoked such interest is that in contrast to many other factors relevant for speech processing (e.g. word frequency, imageability, age of acquisition, etc.) PND is known to have opposite effects on speech perception and production; words in dense neighborhoods are more difficult to perceive, but easier to produce than words in sparse neighborhoods (see e.g. Dell & Gordon, 2003 for a review). More recently, phonological neighborhood density has been invoked as a possible driving factor in the development of segment-based lexical representations. Researchers in phonological development have argued that the lower overall density of young children's lexicons allows them to initially store and access words in a more holistic manner (Charles-Luce & Luce, 1990, 1995; Edwards, Beckman, & Munson, 2004; Logan, 1992; Vihman & Croft, 2007, among others). As words are added to the lexicon, however, the potential for confusion between similar sounding words increases, forcing language learners to pay attention to finer grained phonetic details in order to make the necessary contrasts between lexical items. One potential shortcoming in most studies of developing phonological neighborhoods is that phonological development is considered in the aggregate; in many studies (e.g. Charles-Luce & Luce, 1990, 1995; Logan, 1992) the estimated time course for adding words to the lexicon is based on large corpora of many children. While this approach may gain something in its generalizability, it may also be missing some of the more interesting details that emerge from examining the development of individual children's phonological systems; since each child approaches the learning task based on his or her own experience with language, and his or her own inductive processes, cases studies of individual children's phonological development can shed light on the process by which early phonological generalizations are made and how they eventually develop into a full-fledged phonological system.