Lee, Seunghwan & Oh, Mira. 2004. A Perceptual Account of Consonant Cluster Change in English. English Language and Linguistics 17, 101-116. Historical perspectives have long helped to shape phonological theory and historical phonologists have long sought to test the validity of theoretical models using data from phonological changes. Diachronic evidence has a direct bearing on the nature and status of markedness constraints, which take on a central role in the phonological grammar in the model of Optimality Theory. This paper argues that perception plays a crucial role in consonant cluster changes in English. For instance, consonant cluster simplification testifies that a perceptually nonsalient consonant deletes regardless of its position in the syllable. It is also shown that the OCP results from the avoidance of perceptually similar sounds.