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声的产生,是来源于物体机械振动的传播,使周围的空气受到相应的振动所产生的空气压力的变化,这种变化以声波的形式向周围扩散,当它振动人耳鼓膜时,就使人听到了声音。人耳能听到的声音的频率范围是20～20000赫兹。大于20000赫兹的声称为超声,低于20赫兹的声音为次声。一般来说,超声的波长短,对人体的危害不大;而次声的波长很长,渗透性、穿透力都很强,可对人体构成危害。 医学及生理学研究表明,人体及各器官的固有频率大都在3～17赫兹之间,即都在次声波频率的范围内。当与人体固有频率相同
The sound is generated by the mechanical vibration of the object, so that the surrounding air is subject to the corresponding changes in air pressure caused by vibration, which changes to the surrounding sound waves in the form of dispersion, when it vibrates the human eardrum, it makes Man heard the sound. The frequency range of the human ear can hear the sound is 20 ~ 20000 Hz. Sounds greater than 20000 Hz are referred to as ultrasound and those below 20 Hz are infrasound. In general, the short wavelength of ultrasound, the harm to the human body is not; while the infrasound of a very long wavelength, permeability, penetration are strong, can pose a hazard to the human body. Medical and physiological studies have shown that the natural frequencies of the human body and various organs are mostly between 3 and 17 Hertz, which are all within the range of the infrasound frequency. When the natural frequency with the same body