Visualizing speech production: Professor Suzy Ahn researches tongue and larynx movements across languages

Professor Suzy Ahn’s research delves into the fascinating world of how we speak. Specifically, she focuses on how the tongue and larynx move when producing sounds in different languages. By analyzing the intricacies of speech articulation, this assistant professor in the Department of Linguistics seeks to understand both universal and language-specific patterns in the ways in which humans produce and perceive sounds.

Ahn’s primary interest lies in tongue positioning and larynx movement during the voicing of contrast sounds—such as the distinction between “B” and “P” in English (e.g., bet vs. pet). Ahn compares these phenomena across various languages, including English, Mandarin, Korean, Brazilian Portuguese, Thai, Hindi and Javanese.

A midsagittal ultrasound image of the tongue during the production of 'd'. Identified on the photo from left to right: Tongue root, white curved line: tongue surface, and the tongue tip.

Since joining the University of Ottawa in 2020, Ahn has expanded her research to include Laurentian French, an interest that emerged naturally from interactions with local speakers. For example, her recent project studied vowel laxing in Laurentian French (the most common French in Canada), where words like petit (masculine) and petite (feminine) differ subtly in the pronunciation of the vowel “i” due to the final consonant. She has also recently undertaken a study with Professor Marc Brunelle, focusing on the Raglai language in Vietnam.

Ahn’s data collection begins by inviting adult participants to her lab, where they read a specific script or word list while she records them. Using ultrasound technology, she visualizes the movement of their tongue and larynx during sound production. This lets her investigate how speech sounds are physically produced and to compare articulatory processes across languages. While recruiting participants for her research has been easy through the ISPR student pool, finding native speakers of less common languages like Javanese can be challenging and involves relying on connections with cultural organizations, embassies and social media. In addition to her usual lab research, her recent study on Raglai involved her first fieldwork experience in Vietnam.

A setup of the ultrasound recording session in the Sound Patterns Lab located in the Simard Building (room 333A)

Ahn plans to expand her research program to include bilingual and multilingual speech production, along with child speech production. She is also keen on exploring more advanced methodologies for analyzing ultrasound data.

For Ahn, understanding how speech is physically produced contributes to a variety of fields. It has direct applications in speech pathology, where it can help with diagnosing and treating speech disorders. Additionally, this research can enhance second language learning and offer valuable insights into bilingual speech production. Ultimately, by contributing to our understanding of how we speak, Ahn’s research will significantly improve our knowledge about human communication.