Neuroactive steroids synthesized in the nervous tissue, referred to as neurosteroids, are implicated in the proliferation, differentiation, and survival of neuronal and non-neuronal  cells. One of the neurosteroids, estrogen (an ovarian steroid), reportedly has in the central nervous system exhibited non-reproductive actions such as neuroprotection. Recent studies have clarified that estrogens possess antioxidant properties, regulate apoptosis, and induce protective actions on various organs. Additionally, clinical and experimental studies of the auditory system have indicated that estrogens affect auditory perception and exhibit protective effects on cochlear injury. In this review, we discuss estrogens’ protective actions against cochlear injury. We also summarize the data suggesting that estrogens affect the apoptotic cell-death pathway. In addition, with regard to steroid biosynthesis and the metabolic pathway, we describe the roles of other neurosteroids in cochlear injuries.