My research focuses on phonetic detail within phonology and how it fits into representations. In particular, I establish correlates in production and test whether they are reflected in various dimensions of perception; cue usage can vary across languages and across speakers,
though some of the apparent by-speaker variation is not systematic and disappears with replication.
My second focus is on sound change. Modern perception and production data, in combination with traditional reconstruction and philology, can help establish pathways of diachronic developments.
Phonetics in Phonology
Even when a contrast is described as hinging on a particular characteristic, there are often many acoustic characteristics that correlate with that contrast, which listeners may attend to differently depending on their native language. Awareness of cues is likely to be reflected in two ways: Use of it in identifying the relevant contrast, and compensation for the expected effect when identifying the cue itself. One line of my research is on coda voicing, which has many phonetic correlates, most of which are clear consequences of producing voicing. A smaller number of these characteristics influence listeners' perception of voicing.
Phonetic details in production are influenced by a range of conditioning factors, both phonological and higher level. Part of speech and predictability in context can produce significant differences between homophone mates , but these details are absent when the same words are produced in isolation, suggesting that they are not part of the representation. However, listeners seem able to weakly access memories of these details, performing at slightly better than chance at homophone identification when the words are extracted from sentences. Phonetic distance also has a small effect in discrimination tasks, and is highly sensitive to the particular dimension that is manipulated and whether it is a characteristic that listeners are attending to.
Another line of my research looks at convergence, which provides a look into representations in how input influences subsequent outputs. Elicited shifts are highly shaped by the phonology; shifting one vowel influences neighboring vowels, and shifting one word influences other words with the same sounds, such that opposing shifts across words end up having no effect. Apparent word-specific convergence may result from issues with the difference-in-difference method for measuring convergence, which also can create the appearance of individual differences. However, there is very limited evidence for individual differences in convergence; across measures, there are not some speakers who are more influenced by their interlocutors than others, though some interlocutors are more likely to elicit convergence than others.
Evidence for Sound Changes
There are many parallels between misperceptions of sounds and sequences in laboratory experiments and in known historical changes. While experimental data alone is not sufficient to provide conclusive evidence for pathways of sound change, patterns in perception and production can clarify the relative likelihood of developments and illustrate how they occur. One of the recurring patterns that I am investigating is voicing-conditioned vowel duration; some of the correlates of coda voicing that are neglected as perceptual cues to voicing influence perceived vowel duration, which may provide a pathway for developing voicing conditioned vowel duration.
In addition to broad connections between diachronic phonology and synchronic patterns of errors and variability in perception and production, I also seek synchronic parallels to test specific reconstructions, particularly for changes which lack clearly reconstructed parallels that would provide a foundation for a typology, including the developments of the Proto-Indo-European "laryngeals" and the sound change proposed in Winter's law, with lengthening only before voiced unaspirated stops.
I also have some more traditional reconstruction projects, particularly combining comparative reconstruction and written records to reconstruct sound changes and synchronic patterns in ancient languages of the Neat East.
Currently I am part of a group studying A'ingae, a South American language isolate; we have produced the first instrumentally based overview of its phonological system and continue to elucidate both areally motivated characteristics of its phonology and unique characteristics, such as narrative use of syllable-level falsetto.
As part of my collaboration with the A'ingae fieldwork project, we have been working on reconstructing phonological changes. Although A'ingae has no known linguistic relatives, synchronic allomorphy and limited distributions of sounds suggest several sound changes that substantially restructured the system, including development of contrastive prenasalized stops and development of vowel nasality.