Existing theories about sound change focus either on the role of speakers or the role of listeners. However, members of a speech community are of course both speakers and listeners of their language. This course will investigate the relationship between the production and perception patterns of individual language users in ongoing sound changes. Questions such as the following will be considered: Do the production and perception patterns of an individual speaker change together, or does change in one modality precede that in the other modality? Are innovative speakers (those who drive a sound change) also necessarily innovative listeners? These issues will be explored based on recent research focusing on a variety of languages, including English, Afrikaans, Kera, different varieties of Chinese, etc. Participants will also be encouraged to draw on their own experiences to develop research projects related to this topic.