Study On The Influence Mechanism Of Noise Environment On Human Comfort Under Hypobaric Environment

Acoustic environment is one of the important environmental factors in human work and life. With the continuous improvement of living standards, people’s activities range gradually expanded, in some special conditions, such as, when people take the plane, travel to the plateau, living in the plateau environment, etc., will involve a hypobaric environment. However, the characteristics of the acoustic impedance of the air in the hypobaric environment, some physiological reactions of human, and the subjective feelings of the people are different from those of the atmospheric pressure. Although the noise environment of the aircraft and high-speed trains in the passenger compartment has improved, but still can not meet the requirements of the people. Now a universal meter in sound level of noise evaluation is closest to the feelings of the human ear to loudness, but A-weighted sound pressure level in the high decibel and some complex noise environment is not accurate, and applicability in hypobaric environment should be studied. A suitable and accurate method for hypobaric environment need to be explored.In this paper, we study the various factors that affect the comfort of people in the hypobaric noise environment. The main research contents are as follows:(1) Theoretical analysis is carried out on the aspects of the physical, physiological, psychological, and environmental assessment method of acoustic transmission.(2) Through the experimental questionnaire and heart rate variability analysis, the relationship of the parameters such as the pressure, the noise frequency, the sound pressure level and the noise duration was studied from the perspective of subjective psychology. Finally, a comprehensive analysis is conducted, and the evaluation model of acoustic comfort prediction is established.(3) In order to explore the effect of noise on human subjective loudness mechanism, a mechanical finite element model for simulating sound transmission in middle ear is established, and its reliability is verified. It can be used to verify the feasibility analysis on the subjective and objective parameter for hearing loudness. And it helps to establish a more accurate noise evaluation model.