Cognitive factors involved in preserving a phonemic contrast.

Previous research has demonstrated that semantics and pragmatics influence durational modifications in words and segments. The present research investigated specifically how semantics and pragmatics influence preservation of a phonemic contrast. Experiment 1 examined alveolar flapping in American English. Potentially flapped words, for example, writer and rider, were embedded in each of two types of semantic passages: semantically biasing and semantically neutral passages. In addition, these passages were produced in one of two pragmatic conditions: listener-present and listener-absent. The results showed that the phonemic voicing distinction between /t/ and /d/ was preserved in biasing passages and in the listener-present condition. The /t/-/d/ distinction was not preserved in neutral passages or in the listener-absent condition. Experiment 2 examined whether listeners could use the durational differences found to distinguish phonemic voicing in Experiment 1. Our investigation demonstrates that semantics and pragmatics interact with phonological processes in speech production. We speculate that phonological processes may be affected both by speakers' decision processes to adjust their articulation for the benefit of the listener and by speakers' internal structure and interactive activation among linguistic units.