Fire Safety Science Digital Archive

A stochastic model for analyzing the response of sleeping subjects to sound stimuli whose intensity varies with time is developed, generalizing a model developed in [1] for analyzing the response of sleeping subjects to sound stimuli of constant intensity. The model is used to analyze the results of an experiment carried out by Ball and Bruck [2] to compare the response time of sleeping subjects to three different auditory stimuli. The sound intensity increased steadily with time and the young adult subjects (seven males and seven females) were tested when sober and with blood alcohol levels of 0.05 and 0.08. The analysis revealed that alcohol had a very significant effect in slowing down the response of all subjects. It also revealed that females responded faster than males at all alcohol levels. The great advantage of using the stochastic model is that it permits the estimation of the probability that the response time will exceed high values that may put the sleeping occupant at a severe risk of death or injury in a fire.