Hearing loss is often associated with human immune disorders, including both autoimmune disease and systemic immune complex disease. At present we have very little understanding of the cellular and molecular mechanisms of the ear that are compromised to lead to this deficit. The general aim of the study is to evaluate inner ear morphology, electrophysiology, and immunopathology in mouse models of autoimmune disease and systemic immune complex disease. C3H control mice, C3H/lpr autoimmune disease mice, and C3H mice with induced systemic immune complex disease will be evaluated with auditory brainstem response electrophysiology at ages of 2, 4, and 6 months which are before, during and after onset of autoimmune disease at 3 months. Serum analyse of antinuclear antibody, immune complexes, cryoglobulins, and total globulins will be used to assess systemic disease. Light and electron microscopy of the cochlea will indicate the areas of pathology and light and electron microscopic immunocytochemistry of immunoglobulins and complement will indicate the areas of immunopathology. Corticosteroid therapy will be attempted to prevent the effects of systemic autoimmune disease on the cochlea to identify possible interventional methods. Cochlear electrophysiology, pathology, and immunopathology will be compared in the groups to determine the extent and similarities of cochlear damage with the two immune disease models. The study will allow us to identify the potential inner ear disease mechanisms in human immune disorders. By understanding the sensorineural pathology related to these diseases, we can more effectively intervene in such cases of human inner ear dysfunction.