I study influences speech production and perception from theoretical, applied, and commercial perspectives.
I study speech production and perception in order to identify what environmental, sensory and physical constraints on speech can enhance or interfere with speech perception.
I research how speech speech airflow contacting the skin enhances and interferes with speech perception, much as researchers have done with visual speech since the 1950s. This includes studying speech air flow production, skin respose to speech air flow touch, speech perception enhancement and interference, and brain responses from seeing, feeling, and feeling speech.
I also work on seemingly tiny constraints of speech production in order to understand when and how to account for low-level speech production variability. In so doing, I designed co-collection and co-registration of ultrasound imaging of the tongue and articulometry giving us both shape and point-tracking for the tongue. And in so doing, gained an improved understanding of the tongue's behaviour in speech in relation to gravity, speech rate, and tongue motion complexity.
My goal is to produce a multi-sensory model of speech perception that takes into account the relationship between audio, visual, and tactile speech signal strength, along with low-level speech production constraints.
- Derrick D. and Gick B. (2021) Gait change in tongue movement. Scientific Reports 11(1) http://dx.doi.org/10.1038/s41598-021-96139-4.
- Ying J., Shaw JA., Carignan C., Proctor M., Derrick D. and Best CT. (2021) Evidence for active control of tongue lateralization in Australian English /l/. Journal of Phonetics 86 101039: 1-24. http://dx.doi.org/10.1016/j.wocn.2021.101039.
- Blue WJ., Derrick D. and Blue CL. (2020) The impacts of a community-based health education and nutritional support program on birth outcomes among migrant workers in maesot, thailand: A retrospective review. International Social Science Review 96(3): 1-23.
- Shaw JA., Carignan C., Agostini TG., Mailhammer R., Harvey M. and Derrick D. (2020) Phonological contrast and phonetic variation: The case of velars in iwaidja. Language 96(3): 578-617. http://dx.doi.org/10.1353/lan.2020.0042.
- Strycharczuk P., Derrick D. and Shaw J. (2020) Locating de-lateralization in the pathway of sound changes affecting coda /l/. Laboratory Phonology 11(1) http://dx.doi.org/10.5334/LABPHON.236.
Donald studies speech production and perception in order to identify the phonetic constraints on low-level speech production, and the low-level percepts that can enhance or interfere with speech perception. One of his goals is to develop a theory of phonetic constraints on speech production that allows us to understand when and how low-level speech variability can systematize into sounds with different meanings in a language or dialect. Currently, Donald believes that when listeners can perceive low-level speech variability, it has a chance to become meaningful in that listener’s idiolect.
So far, Donald's research has implications for speech planning, constraints on speech production, and multi-modal speech perception, including the possibility of enhancing speech perception among the hard-of-hearing.