Auditory thresholds for sinusoidal tones were determined in eight patients with adrenal cortical insufficiency (four with Addison's disease and four with panhypopituitarism) and compared to those in normal volunteers. In adrenal cortical insufficiency (ACI) the auditory detection sensitivity is significantly more acute than that of normal subjects over most of the frequency range, but especially in the region of greatest hearing sensitivity of normal subjects, 1,000 to 2,000 cycles per second (cps). Treatment of the patients with deoxycorticosterone acetate decreased serum potassium concentration and produced gains in body weight but did not alter auditory detection thresholds. Treatment with prednisolone or with maintenance doses of carbohydrateactive steroids returned the auditory detection threshold to normal in every patient tested.The mechanism by which carbohydrate-active steroids affect the sensitivity of the nervous system to sound is not known. However, since the senses of taste, smell, and hearing are all affected in similar fashion by their removal and replacement, there appears to be a generalized increase in sensitivity to all sensory stimuli in patients with ACI not receiving steroids. These hormones may play a significant role in maintaining the level of responsiveness of the sensory system to incoming stimuli.