Human Awakening and Subsequent Identification of Fire-Related Cues

Twenty-four college-age male subjects, employed for one night each, were evaluated on their ability to awaken and then identify fire cues. Twelve subjects were exposed to smoke alarm warning signals of three intensities, while a second set of twelve subjects were exposed to a smoke odor, a heat presentation, and a single smoke alarm warning signal. Subjects were, in all cases, awakened by alarms that reached their ears at signal/noise ratios of 34 dB. They were considerably less likely to be awakened by heat, smoke odor, and alarm sounds that reached their ears at signal/noise ratios of 10 dB or less. Upon awakening, subjects repeatedly failed to correctly label radiant heat presentations and smoke alarm warnings as fire cues.