The role of non-phonetic factors in phonetically conditioned sound change

1 Introduction Language is not static, but rather varies from person to person, from place to place, and from time to time. Sound change refers to the process in which sounds in a language change across people, places, and times. Sound change is key to many fields of research. Historical and comparative linguists discover common ancestry by tracing the patterns of sound change across different languages. Anthropologists and evolutionary biologists use these results to track ancient people's divergence and migration. Recent sound changes feed sociological studies that examine variation across groups and individuals. Cognitive psychologists and neuro-biologists explore the mechanisms underlying language perception, and why, despite individual differences in language processing, synchronic language can be relatively homogeneous. 2 The Comparative Method and the Neogrammarian Principle The traditional method of examining sound change is the comparative method, in which cognates (i.e., words deriving from the same historical form) are compared across languages, in order to reconstruct how the original sounds changed to produce the resulting sounds. Example (1) shows a sound change whereby the Old English (OE) c developed into ch. By comparing cognates, we find that the c in these words developed from an original k sound. (2) lists words where this hard c (i.e., k sound) was retained in English, comparable to the similar sound in related languages.