Ewen MacDonald's research expertise is in hearing, speech perception and production, and hearing-assistive devices.
In his Ph.D., he investigated the consequences of the loss of temporal synchrony on speech intelligibility in noise. The loss of synchrony in the auditory system reduces temporal information that is available to a listener's brain and can occur as a result of aging and/or synaptopathy (often referred to as "hidden" hearing loss). After graduating from the University of Toronto, he moved to Queen's University and investigated the role of auditory feedback on control of speech production. This work examined how talkers changed their speech when the acoustic feedback they received was altered in real-time. In 2011, Ewen moved to Copenhagen to take a faculty position at the Technical University of Denmark. There he continued his research into the perceptual consequences of hearing loss and how they can be addressed by hearing assistive devices.
A recent focus of his research has been on the timing of turn taking in interactive conversation and how this can be used to evaluate hearing-aid signal processing.