The Role of Similarity in Sound Change: Variation and Change in Diné Affricates

Studies have often documented an increase in variation and frequency of change in communities undergoing language shift. Segments that are similar across languages appear particularly vulnerable to change through phonemic transfer or subphonemic convergence with a socially-dominant language. However, phonetic documentation of specific changes in minority languages is limited, and what constitutes similarity remains vague. This paper presents a study of incipient sound changes in the Diné bizaad (Navajo) laterally-released alveolar affricates. Variation among proficient speakers points to the relevance of phonetic similarity in these changes, confirmed through acoustic analysis, while the strong correlation with age suggests external pressure, as younger speakers have less exposure to the Diné language and are more likely to substitute English clusters for Diné affricates. Overall, this study shows how multiple motivators can be identified for changes in a threatened language that otherwise appear to be straightforward substitutions from a dominant language.