• The phonetics-phonology interface
  • Learnability and exceptionality
  • Phonologization
  • Intonation

Current projects

My dissertation investigates the perceptual consequences of phoneme marginality; what, in particular, accounts for those consequences; and what they can tell us about the “phoneme”. I'm collaborating with a few people on different parts of this project, including Ashley Farris-Trimble and her Phonological Processing Lab at Simon Fraser University and Hironori Katsuda, a fellow graduate student at UCLA.

Originating as a group project for a seminar on speech production, Matthew Faytak, now at University of Buffalo, Jennifer Kuo, and I are working on a project on how American English taps/flaps affect local F4 — a surprisingly underresearched phenomenon. Our interest in the topic was spurred by Derrick  Gick (2011), which reports that AmE taps are covertly four different articulations, and Warner  Tucker (2016), which reports a large F4 drop associated with some tap/flap productions.

We are currently analyzing paired ultrasound and acoustic data to verify the group project results.

Past projects

For my MA, I modeled the center of gravity (COG) of English /ʃ/ as a variable dependent on phonetic, phonological, prosodic, and lexical factors. I was interested in elucidating the interactions between these variables, and this necessitated creating a model which produces one type of phonetic detail with significant accuracy.

With an operationalization of feed-forwardness (in the Chomskyian sense), I was able to examine how well different grammatical architectures predict my data. I found that a feed-forward, planning model architecture best predicts my data and with a minimum of predictors. This was in contrast to production model architectures, which are less feed-forward and had more extraneous predictors. Somewhat surprisingly, I also found that the inclusion of non-lexical factors negated any direct explanatory power of lexical variables (e.g., lexical frequency). Rather, lexical variables were only found to modulate the strength of other variables, themselves not directly contributing to the output.

My results urge us to conduct more complex experiments where we can consider as many potentially relevant variables as possible. They also suggest that through inclusion of additional variables, we might see explanatory power shifted from main effects to interaction effects, which I argue to be a marker of feed-forward grammatical architecture.

In addition, as COG is directly affected by lip rounding, this project was the first to investigate how realization of noncontrastive features may be affected by different factors than that of contrastive ones. Not only are lexical factors not found to influence realization, as might be expected, stress is also not found to be a significant predictor of COG.

I have worked with Byron Ahn at Princeton University and Emily Gasser and Donna Jo Napoli at Swarthmore College on the phonetic correlates of sounding like a newscaster.

Some interesting results: neither the amount nor proportion of accented words seems to have an effect on the perceived newscaster-ness of a speaker, even though the general intuition is that newscasters emphasize more words. Newscasters spend much less time in the lowest 25% of their range than non-newscasters, and much more time in the middle 50% — but despite this, listeners only attend to the increased time in the middle 50%. Surprisingly, we also found that, although newscasters speak slower than non-newscasters, speech rate has no effect on perceived newscaster-ness.

We argue that these phonetic differences between newscasters and non-newscasters reflects a difference in the goals that each population is attempting to achieve. The mismatch between performance and perceived newscaster-ness we argue to reflect an incorrect/imprecise understanding of what newscasters are attempting to do, conversationally.

The Mainstream American English Tones and Break Indices (MAE-ToBI) model is a very popular model for understanding American English intonation which makes the strong claim that all pitch movements originate in phonology. Byron Ahn at Princeton and I worked together on a project which shows that this claim cannot be entirely true.

Using Guess Who, the children’s game, we elicitied hundreds of yes-no questions in a context where known and unknown information changed in a controlled manner over time. Though yes-no questions are predicted to have only a prominent low tone (L*) on focused words, we observed that many L*s were preceded by high tones unpredicted by MAE-ToBI. Moreover, these spurious movements became less common the less information remained unknown and more common when speakers experienced higher emotional arousal.

The finding of a semanticopragmatic effect shows that American English intonation is not wholly described by MAE-ToBI and calls for further investigation of “non-phonological” pitch events to see if they may also be conditioned by meaningful linguistic variation. We also suggest that our findings invite reexamination of complex pitch accents, such as those comprising both low and high targets (L+H*), as potentially non-atomic.