How stable are patterns of covariation across time?

Abstract Recent research into vowel covariation has suggested that speakers can be identified as leaders or laggers in multiple ongoing sound changes. What remains unclear is how stable a speaker’s patterns of covariation are over time and whether these leaders and laggers of sound changes remain leaders and laggers over time. We employ corpus data from 51 New Zealand English (NZE) speakers who were recorded at two time-points (eight years apart) and explore covariation between 10 monophthongs using principal component analysis (PCA). The results indicate significant stability across the time-points in two unique vowel clusters, suggesting that speakers’ covariation position within their community remains stable over time. The overall covariation patterns also replicate patterns previously observed in a different corpus of NZE, indicating that patterns of vowel covariation observed with PCA can be stable and replicable across multiple corpora.