Functional pronunciation units in English words.

Two distinct factors limit the orthographic regularity of English words: (a) Most characters can correspond to several different sounds and (b) characters can either stand alone or be combined in various ways for pronunciation as a single phoneme. This study addresses the second of these issues through the analysis of a large corpus of English words. Data are presented describing the frequency that each character (or character cluster) functioned in the corpus as a correspondent of a single phoneme rather than being combined with other characters (or decomposed). Examples are provided regarding potential applications of these data in the construction of stimulus materials for cognitive studies, in neuropsychological investigations of dyslexia, and in computational models of word naming.