In Davison v. Department of Defense (S.D. Ohio 1982) 560 F. Supp. 1019, the plaintiffs challenged the sufficiency of an EIS prepared in connection with the addition of civilian air cargo operations at Rickenbacker Air National Guard Base. The "greatest single environmental impact" occasioned by the proposed nighttime air cargo flights was on the sleep of the people who lived near the airfield. ( Id. at p. 1033.) The EIS prepared for the project set 65 Day-Night Average Sound Level (DNL) as the threshold for significant noise exposure and identified which houses would be significantly affected. The court held that DNL, even when coupled with a time-above analysis, did not adequately inform the public about how an increase in nighttime flights would affect sleep in a nearby residential area. The court concluded that while the nighttime "penalty" in cumulative noise calculations gave some indication of the increase in nighttime flights, "the great magnitude of this difference should have been made plain in the EIS." ( Id. at p. 1036.) The court stated: "The reader . . . cannot gain any real appreciation of the potential disruption simply by being told the number of minutes that aircraft noise will occur when all of the overflight peak level events are strung together." ( Id. at p. 1037.) The Davison court cited several technical deficiencies in the EIS. First, the study did not state the number of night flights that traditionally had taken off or landed at Rickenbacker. ( Davison v. Department of Defense, supra, 560 F. Supp. at p. 1037.) Second, it did not estimate the number of times a nearby resident could be awakened by overflights during "normal" or "worst case" nights. Third, the study did not discuss whether residents' sleep disturbance would diminish over time. Finally, the EIS did not address the issue of whether long-term exposure to noise-induced sleep disturbance would result in any important physiological effects. The court pointed out that because these issues would be vital considerations to a decision maker analyzing the proposal, the EIS did not meet NEPA's mandate to explore unavoidable environmental consequences " 'to the fullest extent possible.' " (Ibid.)