Evaluation of users' abilities to recognize musical alarm tones

The problem of accurate identification of alarm sounds in the operating room, recovery room, and intensive care environment has persisted for many years. Monitors made by different companies may have different alarm sounds for the same monitored variable, and similar alarm sounds for different variables. In an effort to illustrate universal alarms sounds, a system of six musical alarm tones was designed with musical themes from popular songs used for oxygenation, ventilation, cardiovascular monitoring, temperature monitoring, artificial perfusion, and drug administration systems. These melodies were played for a group of anesthesiologists and others, who were initially asked to guess the organ system for each melody. The answers were then given to the participants, and after a short delay the melodies were played again in a different order. Seventy-nine response sheets were collected. The expected random score was 1.0±1.0 SEM correct. The observed score on the first hearing was 1.5±1.6 SEM, p=0.01 compared with the random score. The observed score on the second testing was 4.3±2.2 SEM, p=0.001 compared with the first hearing. Indeed, 42 of 79 (53%) respondents got all six answers correct on the second testing, versus three respondents for the first testing. The implications of these findings are discussed in the context of integrated alarm systems used in complex medical environments such as the operating room.