Changes in regional cerebral blood flow (rCBF) have been described as being indicative of local cortical function during the performance of complex psychological tasks. The interpretation of earlier studies are questionable due to the lack of basic research in the area of primary sensory stimulation. The purpose of the present study was to demonstrate rCBF changes in relation to non-meaningful white noise stimulation. The present study used the non-invasive Xenon-133 inhalation technique to define a restricted "metabolic response range" in the posterior-superior temporal region during auditory stimulation. No significant mean increases are reported, but significant changes in the variability of regional responses are documented. The data suggests that patterns of rCBF associated with the performance of complex psychological tasks should be compared to rCBF patterns related to non-meaningful, sensory stimulation and not to uncontrolled baseline studies. The potential of the Xenon-133 inhalation technique as an instrument useful for behavioral study is discussed.