How discourse context shapes the lexicon

Using a corpus of Medieval Spanish text, we examine factors affecting the Modern Standard Spanish outcome of the initial /f/ in Latin FV‑ words. Regression analyses reveal that the frequency of a word’s use in extralexical phonetic reducing environments and lexical stress patterns significantly predict the modern distribution of f‑ ([f]) and h‑ (Ø) in the Spanish lexicon of FV‑ words. Quantification of extralexical phonetic context of use has not previously been incorporated in studies of diachronic phonology. We find no effect of word frequency, lexical phonology, word class, or word transmission history. The results suggest that rather than frequency of use, it is more specifically a word’s likelihood of use in contexts favoring reduction that promotes phonological change. The failure to find a significant effect of transmission history highlights the relative importance of language internal sources of change. Results are consistent with usage-based approaches; contextual variation creates differential articulatory pressures among words, yielding variable pronunciations that, when registered in memory, promote diachronic change.