Effects of noise in simulated high performance aircraft cockpit on healthy volunteers' cognitive ability

Abstract

Objective To discuss the effects of noise in the simulated high performance aircraft cockpit on the cognitive ability of healthy volunteers.Methods Neurobehavioral evaluation systemChinese 3 (NES-C3) was applied to test the cognitive ability of 10 healthy volunteers,who were respectively exposed in 108 dB (A) (J-A group),122 dB (A) (J B group) simulated aircraft cockpit noise environment and in 35 dB (A) (basic noise group) background noise isolation environment.Their basic cognitive ability was respectively tested at 0 min,30 min and 60 min exposure in simulated noise environment.Moreover,National Aeronautics and Space Administration task load index (NASA-TLXL) was conducted to evaluate the effects of noise on mental load of the healthy volunteers.Results ①Under three different noise basic and at 3 different time marks,there was no statistical differences in serial add and subtract index.The comparison of continuous recognition ability index in 30 min exposure showed that the ability index of J-B group was lower than that of basic noise group (t=2.084,P＜0.05),and the ability index of J-B group and J A group was lower than that of basic noise group for 60 min exposure (t=2.222,2.783,P＜0.05 or 0.01).The switching attention ability index of J-A and J-B groups was lower than that of basic noise group (t =3.614,2.342,P＜0.05 or 0.01) for 30 min exposure,and the switching attention ability index of J-B group lower than that of basic noise group (t=2.823,P＜0.01) for 60 min exposure.Such ability of J-A group in 30 min exposure and J-B group in 60 min exposure was respectively was lower than that of at 0 min (t=2.583,2.222,P＜0.05).For the comparison of vision complex reaction time,the ability index of J-B group in 60 min exposure was lower than that at 0 min (t=2.369,P＜0.05),as to the test at 30 min and 60 min exposure the ability index of J-B was lower than that of basic noise group (t=2.232,2.961,P＜0.05 or 0.01).②Under three noise backgrounds and at 3 different time marks,there was no statistical difference in mental demand and performance.For the comparison of physical demand,the ability index of J-B group was higher than that of basic noise group at 30 min and 60 min exposure (t=2.082,2.154,P＜0.05).The ability index of J-B group was higher than that of the basic noise group at 0 min and 30 min on the comparison of temporal demand (t=2.793,2.792,P＜0.01).For the comparison of effort,the ability index of J-B group was higher than that of basic noise group (t=2.793,P＜0.01) and J A group (t=2.792,P＜0.01) at 30 min exposure,J-B group's index was higher than that of basic noise group (t=3.572,P＜0.01) and J-A group (t=2.901,P＜0.01) at 60 min exposure while J-B group's index at 60 min exposure was higher than that at 30 min (t=2.223,P＜0.05).The frustration level index of J-B group was higher than that of basic noise group at 0 min and 60 min exposure (t=2.681,2.139,P＜0.05).Conclusions The noise levels equivalent to simulated high performance aircraft cockpit environments would reduce the recognition ability of volunteers in a certain extent,and the condition would be worse with the increase of noise duration and intensity.Therefore,it is suggested to take effective methods such as noise reduction in aircraft cockpit and mental intervene to pilots so as to decrease the influences of high performance cockpit noise on the recognition ability of pilots. Key words: Noise, occupational; Questionnaires; Cognitive ability