Accent detection is a slippery slope: Direction and rate of F0 change drives listeners' comprehension.

The present study tests whether listeners use F0, duration, or some combination of the two to identify the presence of an accented word in a short discourse. Participants' eye movements to previously mentioned and new objects were monitored as participants listened to instructions to move objects in a display. The name of the target object on critical trials was resynthesized from naturally-produced utterances so that it had either high or low F0 and either long or short duration. Fixations to the new object were highest when there was a steep rise in F0. Fixations to the previously mentioned object were highest when there was a steep drop in F0. These results suggest that listeners use F0 slope to make decisions about the presence of an accent, and that F0 and duration by themselves do not solely determine accent interpretation.