Dr. Keith Leung and the Importance of Research Experience

October 03, 2022

How did you end up in linguistics and what was the journey like for you?

I spent a year in Thailand after completing my undergraduate study. When I was learning Thai, I began to analyze the language and compare it with my first language in order to facilitate my learning. It was a very enjoyable experience, and I started to think about doing a graduate degree in linguistics. My MA thesis focused on code-switching and lexicosyntactic transference, but at the same time I was also fascinated by speech acoustics and perception. Therefore, I switched to investigating the perception-production relationships of speech sounds in my Ph.D. study.

What was your experience like at SFU?

SFU Linguistics offered me a very supportive graduate study and research environment. The program equipped me with the skills to conduct research and disseminate research findings. I had the opportunity to be the manager of the LABlab and led several projects that enriched my research experience. The most exciting part of my study was presenting in local and international conferences where I could gain insights from other researchers. Without the support of the department and my supervisor, I wouldn’t have been able to attend these conferences. Being able to receive instructional training (ISW, CPUTL) and had the actual teaching opportunities (Sessional, TA) were extremely valuable as well.

Tell us what your thesis topic is about and what got you interested in the topic.

My thesis is about the relationship between perception and production of lexical tones. Even though it sounds intuitive that perception and production should be related, I was puzzled when I found some previous studies that did not find a perception-production link. Therefore, I wanted to explore the factors that could relate the two domains. My thesis project focused on the critical status of perceptual cues in establishing a perception-production relationship. Using Mandarin tone cues, I found a perception-production link for critical perceptual cues for native Mandarin tone perception, but not for non-critical perceptual cues.

What are your plans now that you have completed your Ph.D.?

I am now the Research Facilitator at Kwantlen Polytechnic University (KPU). My role is to support researchers to establish research agendas and promote KPU’s research and scholarly activities.

Do you have any advice or tips for undergrads who are thinking to go into a graduate program?

I strongly encourage undergrads to become an RA of one of the research labs in the department. You will gain important research experience, meet graduate students and find out whether graduate study is right for you.

Dr. Leung's PhD Thesis

Perception-production relationship of lexical tones:


The link between perception and production is predicted to be close, but empirical findings on this relationship are mixed. While a perception-production relationship has been found for various speech sounds, some research has failed to support such a link. To explain this apparent contradiction, a proposed view is that a perception-production relationship should be established through the use of critical perceptual cues. This dissertation project aims to examine this view by using Mandarin tones as a test case, since the perceptual cues for Mandarin tones consist of a perceptually critical pitch direction cue and a non-critical pitch height cue. As there was little research on the perception-production relationship of lexical tones based on acoustic cues, the first study explored the correlation between perception and production of Mandarin Tone 2 for each of five acoustic cues which included critical pitch direction-related cues, non-critical height-related cues and a temporal cue. A perception-production correlation was only found for the critical perceptual cues. The second study investigated the proposal systematically by examining the defining features of critical and non-critical perceptual cues and the perception-production relationship of each cue for each Mandarin tone. The perceptual stimuli in the perception experiment were created by varying one critical and one non-critical perceptual cue orthogonally. The cues for tones produced by the same group of native Mandarin participants were measured. This study found that the critical status of perceptual cues primarily influenced the within-category and between-category perception for all tones. Using cross-domain bi-directional statistical modelling, a perception-production link was found for the critical perceptual cue only. A stronger link was obtained when within-category and between-category perception data were included in the modelling, as compared to using between-category perception data alone, suggesting a phonetically and phonologically driven perception-production relationship. Finally, the third study examined if forming a perception-production relationship could be clearly attributed to the use of critical perceptual cues. Using the same critical and non-critical cues as in the second study, the learning effects on the perception and production of each cue were measured for Mandarin learners whose native language was Indonesian, a non-tonal language, in a four- to six-week interval. A simultaneous improvement in perception and production was found for the critical perceptual cue only, supporting the notion that the critical perception cue was a contributing factor driving the link between perception and production.