In hearing and balance organs, hair bundles convert mechanical input, caused by sound or head movement, into electrical output that is transmitted to the brain. Because this conversion is an essential step in hearing and balance, many forms of hearing and balance impairment are caused by hair-bundle dysfunction. Hair bundles differ in their structure depending on the sensory input they have evolved to detect, but we do not understand how a hair bundle’s structure determines its function. To learn how a hair bundle’s structure controls its function, we are building computational models of hair bundles with different structures. Computational models constructed by the Ó Maoiléidigh lab are informed and tested by experimental observations in the Ricci lab. These models will help us to understand how defects in hair-bundle structure lead to hearing and balance impairment and suggest new treatments for hearing loss and balance disorders.