Studies On Synthetic Assessment Method Of Noise Based On Human's EEGs And HRV

The noise pollution is the main object of the environmental pollution which should be controlled in the 21st century, and the noise standard provide basis for controlling noise. The A sound level on influencing humans' hearing sense normally adopt as an index in current noise assessment standards, though psychological and mental influence is neglected. Therefore, the aim of this dissertation is to establish a noise synthetic assessment system, based on studies of influences of humans' heart rate variability (HRV) and brain waves (EEGs), combined with current noise standards and researches on the traditional noise index of hearing loss, in order to assess these influences on human caused by noise, more scientifically and all-sided.The research method of this dissertation is: new methods are applied not only on human body's HRV for measuring heart load and nerve function but also on EEGs, for developing reflect the influence on human nerve system caused by environmental change. For the first time, the influence regulations of HRV and EEGs caused by the whole frequency region of noise are acquired through this method. A new synthetic system of noise fuzzy assessment is established, on the base of the fuzzy assessment theory, combined with hearing loss, the regulations of the HRV and EEGs, which fully considered overall influence on human body affected by the other physiological, psychological and mental factors besides hearing loss.The main contents and conclusions drawn in the dissertation:1,I acquire marked regulations of the human's HRV, EEGs and subjective evaluation caused by noise for the first time, from experiments on human body's HRV and EEGs affected by noise in the range of sound frequencies.2, The synthetic system of noise fuzzy assessment with many levels of structure and many factors was established creatively, based on fuzzy theory.Many innovations were in the established process at noise assessment, such as established mathematics model and model index system, settled parameter and powercoefficient.3, " The analytic system of HRV" and "The synthetic system of noise fuzzy assessment" were developed to analyze human body's HRV and have a noise fuzzy assessment, by the program environment of Lab VIEW. And "The analytic system of HRV" can also be used to analyze HRV at other occasions. The programs have some features of a plain level of structure, a perfect function and scientifically calculating method etc., and form a power system about noise analysis and assessment by computer.4, Finally, the synthetic system of noise fuzzy assessment developed was used to assess noises of a woodworking sander, planer, fretsaw, obtaining their noise assessment results. The results are taken as the base to decline effectively the noise of the woodworking machines and a dependable science groundwork to control noise synthetic influence to human body.This research gets the assessment of the degree of the hurt by combining the actual problem in domestic and international research on noise and the inquisition, experimental and theoretical study to get methods to solution and conclusions with theory value for the synthetic assessment of noise. This dissertation obtained the corresponding quantitative analysis from the aspects of medical physiology, medical psychology and engineering psychology. It provides a new idea for assessing noise endangers completely.