On the visual distinctiveness of English words

Abstract

Lipreading is facilitated when words are visually distinct. It has been established [Auer and Bernstein, J. Acoust. Soc. Am. 102, 3704–3710 (1997)] that words in the English lexicon manifest a low degree of visual similarity: most words remain visually unique, even when distinctions are collapsed across phoneme classes, as is characteristic of visually perceived speech. But, is the high degree of visual uniqueness a distinctive (nonaccidental) property of the English lexicon? Perhaps not: the lexical space of English is large, both in crosslinguistic terms and in absolute terms. In other words, many lexical slots exist; a fairly low percentage of them are filled by actual words [Hockett, 288–290 (1958)]. Therefore, the high degree of visual distinctiveness might be an ‘‘accidental’’ property of the lexicon, deriving from the segment inventory and phonotactics of the language. This study will explore this question by comparing the visual similarity properties of words in simulated (hypothetical) lexicons to those of words in the actual English lexicon. Each novel lexicon will be generated on the basis of the phonotactic patterns of the actual lexicon. The modeled lexicon is PhLex, a 30<th>000-word phonologically transformable lexicon of American English [Seitz, Bernstein, and Auer (1995)].