Concurrent white noise and acute hypobaric hypoxia: Effect on aviation cognitive performance

Abstract

Introduction: Optimal cognitive performance is the essence of effective execution of a flying mission. Effects of two commonly encountered aviation stressors, hypoxia and noise, on performance have been studied. However, studies on effects of concurrent dual effects of both these stressors on key cognitive parameters are sparse; hence, the objective was to examine these effects. Material and Methods: Cognitive performances were assessed among 30 healthy volunteers (28 males and 2 females) sequentially in four different conditions – baseline (without stressors), 85 dB(A) noise, 14,000 ft altitude, and concurrent exposure to 85 dB(A) noise at 14,000 ft altitude. White noise was simulated through software, altitude in the hypobaric chamber and cognitive performance was assessed with tests from Psychology Experiment Building Language (PEBL) test battery. Data were analyzed using descriptive statistics and repeated measures ANOVA. Results: The study revealed statistically significant direct detrimental effect of altitude and noise on implicit reaction time independently as well as concurrently. However, there was insignificant interaction effect between the dual stressors on implicit reaction time. There were no statistically significant effects of dual stressors on implicit correctness, visuospatial working memory, and selective attention. Although statistically not significant, noise enhanced the performance level in the form of increased Corsi block memory span and Corsi block total score. Conclusion: No significant effect of the dual stressors was observed on most of the cognitive parameters. However, implicit reaction time, a measure of pilot’s risk-taking behavior, was found to be significantly affected by the dual stressors. Further research with a larger sample of aircrew population who differ in age, experience, and other potentially influencing factors is recommended.