Professor Catherine (Cathi) Best

Chair in Psycholinguistic Research

How we learn and recognise spoken language.

Catherine Best’s research is creating new understanding about how our language environment affects speech perception, speech production, word recognition and learning.

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Infants start to acquire some aspects of language even before birth, and quickly develop the ability to distinguish between different speech segments (consonants and vowels) and accents in their mother tongue.

So why do adults find it so hard to perfect their accent in a non-native language, or hear the breaks between words in a stream of foreign conversation?

Psycholinguist Professor Catherine T Best is creating new knowledge about how and when infants learn to recognise words in their native language, even across talker and accent variations, and why, as they age, this makes learning other languages past childhood difficult.

Knowing the answers to these questions is central to understanding the human capacity for language and language learning and how it is shaped by experience with specific languages and regional accents.

Professor Best studies babies’ non-verbal behaviours to track their interest in words and sounds. Their level of interest indicates whether they have mastered a word, and can be used to measure whether they recognise words that contain different speech segments, such as those from another language. She also investigates adults’ perception of spoken elements of unfamiliar foreign languages as well as unfamiliar regional accents.

This work helps in understanding how adults’ and infants’ experience with their native language shapes their perception and production of the basic building blocks of spoken words: consonants, vowels and intonation, the melodic and rhythmic patterns of words and sentences.

Professor Best and her students used these methods to study speech perception for people who speak a single language as well as second language learners, those who speak multiple languages, and children with language difficulties. They have also studied sign languages, facial expressions, and culture-specific characteristics of music.

The best part of my job is discovering new knowledge about this central aspect of being human, the ability to comprehend and speak our native language.


Professor Best is best known for her theoretical contribution to psycholinguistics. Her model of how language experience shapes the perception of spoken languages, the Perceptual Assimilation Model, has offered important insights into why adults, but not young children, often find it difficult to learn other languages and why they often speak them with an accent from their native language.

Her work has been cited in training materials for students of psycholinguistics, speech pathology and developmental psychology, and underpins the development of various tools for addressing language deficiency. She was one of a team that developed a short form version of the Australian English Communicative Development Inventory (OZI), a parent report tool for assessing language development at 12 to 30 months.

Why it matters

Professor Best’s research has improved theories about human speech and language. It has offered important insights into why adults, but not young children, often find it difficult to learn other languages and why they often speak them with an accent from their native language.

She has helped shed light on how we can understand spoken words in our own language or languages across many different and even unfamiliar regional accents.

This new knowledge is critical to developing ways of identifying and treating developmental language disorders, as well as language deficits arising from stroke and brain damage.

It is also important for helping people to learn other languages, and for refining teaching methods to help adults improve their ear and accent.


After receiving her PhD in Developmental Psychology and Neuroscience (Michigan State University, 1978), Professor Best was awarded a prestigious NIH postdoctoral fellowship grant (1978-1980) to study psycholinguistics at the world-renowned Haskins Laboratories, where she was supervised by two central figures in speech perception research: Alvin Liberman and Michael Studdert-Kennedy.

From there, she served for four years as the Director of the Neuroscience & Education program at Columbia University (1980-1984), and then took up a faculty position in Psychology at Wesleyan University (1984-2004). She then joined MARCS Laboratories, University of Western Sydney (now MARCS Institute, Western Sydney University), as Chair in Psycholinguistic Research in late 2004.


  • Leader, MARCS Institute Speech Production Laboratory (MISPL)

Qualifications and Recognition

  • BS, Michigan State University
  • MA, Michigan State University
  • PhD, Michigan State University
  • Individual NIH Postdoctoral Fellowship grant, Haskins Labs (w/ Alvin Liberman and Michael Studdert-Kennedy)

Key publications

  • Best, C. T. (2015). Devil or angel in the details? Complementary principles of phonetic variation provide the key to phonological structure. In J. Romero & M. Riera (Eds.) Sounds, representations and methodologies: Essays on the phonetics-phonology interface [Current Issues in Linguistic Theory series], pp. 3-31. John Benjamins: Amsterdam.
  • Best, C. T., Tyler, M. D., Gooding, T. N., Orlando, C. B. & Quann, C.A. (2009). Development of phonological constancy: Toddlers’ perception of native- and Jamaican-accented words.  Psychological Science, 20, 539-542. doi: 10.1111/j.1467-9280.2009.02327
  • Best, C. T., Goldstein, L., Tyler, M. D. & Nam, H. (2016). Articulating what infants attune to in native speech. Ecological Psychology, 28, 216-261. 10.1080/10407413.2016.1230372
  • Best, C. T. & Queen, H. F. (1989). Baby, it's in your smile: Right hemiface bias in infant emotional expressions. Developmental Psychology, 25,  264-276.
  • Derrick, D., Carignan, C., Chen, W., Muayiwath, S., & Best, C. T. (2018). 3D printable ultrasound transducer stabilizer. Journal of the Acoustical Society of America: Express Letters, 144(5), EL392-398. doi: 10.1121/1.5066350

Perceptual Assimilation Model background

  • Speech perception and linguistic experience: Theoretical and methodological issues in cross-language speech research, pp. 167-200. York Press: Timonium MD.
  • Best, C. T. & Tyler, M. D. (2007). Nonnative and second-language speech perception: Commonalities and complementarities. In M. Munro & O.-S. Bohn (Eds.) Second Language Speech Learning, pp. 13-34. John Benjamins Publishing: Amsterdam.
  • Tyler, M. D. & Best, C. T. (in press 3/2023). The Perceptual Assimilation Model (PAM) and early bilinguals. To appear in Amengual, M. (ed.) The Cambridge Handbook of Bilingual Phonetics and Phonology. Cambridge University Press: Cambridge UK


Phone +61 2 9772 6760
Location Western Sydney University Westmead campus
Room U.5.36