Rule-governed missing information in spoken word recognition: schwa vowel deletion.

Vowel deletion is a phonological process in which an unstressed /inverted e/ (schwa) vowel is deleted during pronunciation. In Experiment 1, vowel-deleted and vowel-reduced versions of two- and three-syllable words rated for pronunciation acceptability showed reduced acceptability for deleted vowel versions with a greater decrement for two-syllable words. Experiments 2 and 3 used vowel-intact and vowel-deleted productions preceded by themselves (repetition prime), their alternative production (variant prime), or a control (unrelated) prime. Lexical decisions to three-syllable vowel-intact and vowel-deleted targets, as well as to two-syllable vowel-intact targets, showed greater priming in the repetition conditions than in the variant conditions. Two-syllable vowel-deleted targets, however, showed comparable repetition and variant priming. The results are discussed in terms of lexical activation and representation of phonological variants. A model is offered in which activation based on similarity triggers utilization of phonological inferences only when required for successful recognition.