Recent studies by researchers, governmental agencies, and safety organizations have recognized a deficiency in the performance of medically related audible alarms [1-4]. In the clinical setting, care providers can suffer from alarm fatigue, a condition in which audible alarms in an operating room are perceived as a nuisance. In this study, we explore the auditory features associated with current audible alarms using tools from the music information retrieval community, and then we examine how those auditory features correlate to listeners' perception of urgency. The results show that aperiodic changes in the auditory spectrum over time are the most salient contributor to the perception of urgency in sound. These results could inform the development of a novel standard regarding the composition of medical audible alarms.