The Laboratory Study On Infrasound Induced Stress And Involved Mechanism

There have been a large number of reports on the effects of noise on the human body .Recently, further advancement in the industrialization of society have aroused great interest in new environments problems on the effect of infrasound.Although, in acoustical physics, infrasound, which is an aerodynamic fluctuation, may be understood as an extension of the effect of noise in the audible frequency range, but its effects on the body cannot be evaluated by the methods applied to audible noise. One of the reason for this difficulty in evaluation of the effects of infrasound is multiplicity of the sensation aroused by infrasound; in addition to tonal response, it is felt as vibration and pressure.This paper is composed of two parts. In the first part, an infrasonic pressure chamber system was established. The chamber has a floor area of 0.88 m~2 and an effective air capacity of 0.86 m~3. To generate infrasound the output of the function generator(1110B,BeiJing Intensity Environment Institute) was amplified by the power ampIifier((7101,No.702 Institute of Spaceflight Co. ) and fed to four 50cm loudspeakers(YD500-...