Lateral and rhotic consonants have been known to pattern together as liquids since the Ancient Greek grammarian Dionysius Thrax (Walsh 1997; Proctor 2009). Synchronic and diachronic processes which affect one liquid in a language are likely to affect all liquids in the language. The English rhotic [r\] has been shown to epenthesize in post-vocalic environments, such as in idear or drawring, a phenomenon known as intrusive-R. This rhotic also lenites in other dialects in words like quart and mother (Gick 1999). In parallel, the English lateral [l] may be epenthesized in a rarer, but documented, phenomenon known as intrusive-L, which affects the same environments as intrusive-R (Gick 2002). Similarly, coda-L is optionally pronounced in some words such as folk, palm, and calm, suggesting a similar process of lenition.

While it is well-established that the English rhotic [r/] may serve as the syllable peak in certain words such as church, bird, and verb, little work as investigated the possibility of a lateral syllable peak in analogous words such as milk, filled, and help. The current study examines coda-position liquids in closed syllables from native California speakers in the Santa Barbara Corpus of Spoken American English (Du Bois et al. 2000, 2003, 2004, 2005) to create a model predicting liquid sonority based on liquid type, speaker gender, lexical stress, and other phonological features. Additionally, following MRI work by Gick et al. (2002), the formant values of liquids are examined to determine the similarity of liquids to vowels and the influence adjacent vowels may have on the shape of a liquid. Given that coda-position [r/] may be the syllable peak in certain closed syllables, we expect coda-position [l] to behave similarly. Finally, since the findings of Gick et al. (2002) suggest that the articulation of /r// and /l/ are most similar to /[schwa]/ and /[open o]/, respectively, it is predicted that the formant structure of these sonorous liquids will mirror the formant structure of these two vowels. The results indicate that liquids in Californian English exhibit similar patterns regarding sonority under certain conditions, although rhotics may be more vowel-like than laterals.