Assessing functional links between speech production and perception in multilingual speakers

The relationship between speech production and speech perception capacities is highly debated. The picture is complicated further by studies of second language acquisition, where development of speech perception is not always accompanied by proportional gains in speech production, and vice versa. This thesis tests functional links between speech production and perception in multilingual participants by assessing speech motor control. Speech motor control highlights a functional link between the speaker's speech production and perception capacities, as they monitor the acoustic properties of their produced speech. A change in the formant frequencies of the perceived vowel (induced artificially by altered auditory feedback) can be associated with a change in production to offset the perturbation. This response is termed adaptation. The data in this thesis comes from four behavioural experiments. The first experiment is a categorical perception study comparing the midpoint of categorical perceptual boundaries to the midpoint of vowel production distributions in English and Spanish within individual Spanish/English bilingual participants. The next three experiments use altered auditory feedback in unbalanced bilingual and trilingual populations (Spanish/English and Spanish/Basque/English). The results of these experiments show that perceptual and production boundaries tend to be located near each other in auditory space, indicating a general functional link between vowel production and perception. The manifestation of that functional link in real time (the adaptation response) varies depending on the task language and the dominant language of the participant. Hearing altered feedback in the dominant language was associated with stronger adaptation. The data here also indicate that the adaptation response can be transferred into productions of an unperturbed nearby vowel in the other language. These findings suggest a separation between speech motor feedback control and the feedforward generation of new speech motor movements, with implications for the design of models of speech motor control and language learning.

Name dc:type.qualificationname

Doctor of Philosophy (PhD)

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

University of Cambridge

Year dc:date.issued

2024

Author dc:creator

• Rees, Madeleine

Advisors dc:contributor.advisor

• Post, Brechtje
• Davis, Matthew

• Speech motor control
• Altered auditory feedback
• Multilingualism
• Speech production
• Speech perception

Licence

• https://www.repository.cam.ac.uk/bitstreams/00ae77f3-f7c0-4b50-83fa-3f8abbfedb0e/download
• https://creativecommons.org/licenses/by/4.0/

Language dc:language

eng

DOI dc:identifier.doi

https://doi.org/10.17863/CAM.112017

OAI identifier oai:identifier

oai:www.repository.cam.ac.uk:1810/373683