The technical term is "aerodynamic noise". Aerodynamic noise can be divided into linear and nonlinear. The linear part includes thickness noise and load noise, and the nonlinear part refers to the noise generated by eddy current and turbulence. This phenomenon mainly includes linear thickness noise and nonlinear noise (Karman vortex street will be produced when electric wires are regarded as infinite cylinders, and Karman vortex street will be produced by submarine cables). Principle of thickness noise generation: When the airflow flows from the leading edge to the trailing edge of the conductor, the airflow will be exhausted by the conductor first, reach the thickest part of the conductor, and then replenish the surface of the conductor. This displacement, compensation, displacement, compensation ... this produces the pressure pulsation of the airflow around the wire. Noise is sound, and the essence of sound is the pressure fluctuation of airflow. What we usually see and hear is mostly structural noise, engines, boilers, cars … so we are not familiar with this concept. This concept was put forward by "light dome" in 1952. Because of this contribution, he was elected as a young professor and chairman of the International Society of Mechanics, and finally he drowned in swimming. The story about aerodynamic noise can be searched, which is quite interesting. The theory of aerodynamic noise is basically stagnant, and there is no big discovery. For example, when people are waiting for a bullet train, the "whoosh" sound it makes when it passes is aerodynamic noise. When you understand the noise, it is easy to understand the noise by thinking about how the air pressure fluctuates. When the wind blows through the wire, it will produce a vortex behind the wire, and the vortex will break away, so the cycle of not breaking away and breaking away changes, so the wire vibrates and produces waves, and people hear the sound of the wire.