Audible alarm signals for anaesthesia monitoring equipment.

To address the problem of auditory alarms on anaesthesia monitoring and delivery devices whose signal is masked by the noises of other operating room equipment, a set of signals having the characteristics of spectral richness, frequency modulation, and temporal patterning were electronically generated, and were tested for detectability against operating room equipment noises in a laboratory setting. A set of signals was identified which can, under these circumstances, be detected with at least 93% accuracy at -24 dB signal-to-noise ratio.