Figure 1.
The auditory system is a distributed, but integrated, circuit. Key to this framework is the rich series of afferent (ear-to-brain/bottom-up) and efferent (brain-to-ear/top-down) projections that pervade every station along the auditory pathway—including to and from the outer hair cells (inset). These pathways contain primary (darker colors) and nonprimary (lighter colors) divisions of the auditory system, and facilitate both sound processing and neural plasticity. Successful auditory learning engages cognitive, sensorimotor, and reward networks, and the intersection of these circuits guides neuroplasticity.