AUDITORY REFLEX THRESHOLDS ELEVATED BY STRESS-INDUCED CORTISOL SECRETION

To study steroid effects on auditory perception, 24 volunteers were un expectedly confronted with a psychological stressor. Auditory reflexes to pure tones and noise were recorded before stress exposure, up to 1 00 min afterwards and in a second control session. Repeated measuremen ts of cortisol and testosterone in saliva, as well as blood pressure, heart rate, and subjective feelings confirmed the stressful nature of the test. Following stress induction the auditory reflex of the contra lateral ear needed significantly higher loudness (i.e. more decibels) to be elicited than at baseline or control measures. Two lines of evid ence suggest that this stress-induced change may be specifically relat ed to glucocorticoid actions: (1) In a previous study similar elevatio ns in auditory reflex threshold had been obtained by the administratio n of exogenous glucocorticoids (hydrocortisone), and (2) in the presen t study the overall effect of stress induction on acoustic reflex desc ribed above was mainly observed in a subgroup of subjects, who respond ed to the stressor with a marked rise in free cortisol.