Delphine Dahan

I am interested in understanding how people make sense of the speech they hear so rapidly and accurately despite the large variability in the physical realization of words. My students and I have been using an eye-tracking methodology to assess people's interpretation of speech as they hear and process it. Participants' eye movements to visually present objects are monitored as participants follow spoken instructions to select one of the objects. People typically fixate on a few of the displayed objects before selecting the named object but usually remain unaware of where their gaze falls. Analysis of their fixations over time, however, uncovers their on-going interpretation of the speech. Our work has revealed listeners' exquisite sensitivity to the acoustic detail present in the speech they hear, with a temporal grain that would be difficult to attain with other methodologies. Furthermore, by analyzing fixations to objects other than the named one, we have demonstrated that listeners adjust their representations of words (as opposed to their interpretation of the speech signal) to reflect their past experience with a talker's speech.