Source of ultrasonic frequency

The energy that the ultrasonic wave itself has, during the process of sound wave propagation, the medium that is propagating the sound wave absorbs a part. As for how much energy is absorbed by the grazing, it is determined by the nature of the medium. It is reasonable to say that the energy of sound waves is absorbed more in the gas, less grazing in the liquid, less absorption in the solid (for example, in metals, quartz crystals, etc.), and the higher the frequency of vibration, It means that the higher the sound, the more energy is absorbed. When the band is far from near or from far to far, the sound heard is a good example of the principle of sound wave absorption. As the distance increases, the first high sounds, such as flute and flute, then the midrange The cornet and the midrange violin, when the distance is very far, only the low drum sound can be heard at this time, the ultra-low sound conveys extremely far, and the ultrasonic wave is also suitable for this principle: the higher the frequency, the more the absorption, and The shorter the distance that ultrasonic waves can travel. The upper limit of ultrasonic vibration is about 100 billion Hz. The ultrasonic wave with higher frequency than this figure absorbs much. According to the above description, it can be estimated that the appearance of the acoustic wave transmitter is completely silent. However, this upper limit has not been reached yet. Over. At present, the extremely high frequency of ultrasound is obtained by the Soviet scientist Professor Dr. Sokolov in actual research, and the frequency is about one million hertz.