Ongoing projects

Phonetic cue weighting under divided attention
(Advised by Dr. Alexandra Jesse and Dr. Lisa Sanders)

Much of our knowledge of speech perception came from experiments conducted in highly controlled environments. However, in real life, listeners’ attention is not always entirely dedicated to speech, differing from the typical setup of perceptual experiments.

This study aims to investigate how divided attention affects speech perception, such as in some classroom scenarios. We ask participants to perform a secondary task and a speech perception task to answer the following questions:

Does distraction interfere with the early perceptual processing of speech or the retention of speech percepts in memory?
What characteristics of distractors influence the nature and extent of such interference?

Testing the roles of post-consonantal F0 perturbation and noise in tonogenesis
(Advised by Dr. Lisa Sanders)

F0 perturbation caused by adjacent consonants is thought to be a possible trigger of tonogenesis, i.e., the emergence of tone in initially non-tonal languages. During this process, the F0 difference presumably becomes larger in magnitude and longer in duration, making it perceptually more salient. Thus, listeners may possibly increase the perceptual weight of F0 while decreasing the weight of consonant phonation.

Using English stop voicing as a testing case, this study examines cue weightings of VOT and F0. Specifically, we ask:

Does the temporal extent of F0 perturbation contribute to voicing perception?
As F0 is more robust to noise, does the presence of noise modulate the F0 perturbation effects?

ERP responses to violations of morphophonological rules, phonological expectations, and phonetic cues
(PI: Dr. Lisa Sanders; Co-PI: Dr. Alexandra Jesse)

The phonetic realization of the English regular plural suffix is determined by its preceding context. When the stem ends with a non-sibilant sound, the suffix and the preceding sound agrees in voicing. It surfaces as /z/ after voiced sounds (e.g., [dogz] ‘dogs’) and /s/ after voiceless sounds (e.g., [kæts] ‘cats’).

By presenting listeners with various types of violations of this morphophonological rule, this study aims to determine:

the representation and processing of allomorphs during speech comprehension
whether congruency of phonetic cues and phonotactic status influence morphophonological processing
how predictability modulates other factors