A relatively low cost, bedside, portable, microcomputer based system for long-term monitoring of human auditory evoked responses in critical care environments is described, and test data are presented. The system enables the user to acquire responses, detect significant peaks (usually peaks I, III, and V), store information and display trends (latency vs time graphs) automatically. Prior to processing, responses are digitally filtered so that no phase distortion is introduced. A peak detection algorithm takes into consideration both the different morphologies of the IV-V wave complex and the time-varying characteristics of the ABR waveform. Evaluations using normal subjects and intensive care unit patients show the clinical potential of automated long-term auditory brainstem monitoring. Physiological monitoring Auditory brainstem response Evoked potential Microcomputer based medical instrumentation About the Author-EDwm MISKIEL, B.Sc.E.E. (1982) M.S. (1986). Mr. Miskiel is currently employed as a research scientist by Artificial Hearing Systems Corp., in Miami, Florida. His main fields of research are automated auditory brainstem response threshold detection, automated behavioral hearing testing for infants, and artificial hearing devices.