Van der Feest studies how young children learn the relevant sounds and sound structures of their native language(s), and how children use that knowledge for recognizing and producing spoken words. In addition, her research investigates speech perception and word recognition in adults, and in listeners with different types of language and dialectal backgrounds. Her work has been published in journals such as Phonology, Journal of Phonetics, Infancy, and Language Learning and Development.
She was previously a research associate and lecturer at the University of Texas at Austin, where she served as the director of the Child Language Lab Austin. She has taught courses on Language Acquisition, Speech Perception and Cognitive Science in the Department of Linguistics and Department of Communication Sciences and Disorders at UT Austin; in the Psychology Department at Villanova University; and at the Radboud University Nijmegen. She was a visiting researcher at the University of Amsterdam, and conducted her postdoctoral research at the University of Pennsylvania.