What is the reason for the loud roar of high-speed engines?

What is the reason for the loud roar of high-speed engines? What is the reason for the loud roar of high-speed engines? There are several reasons for the excessive noise of automobile engines: 1. Noise caused by acceleration: The best way to know whether the noise is normal is whether you have heard the noise before. If the sound of the whole vehicle is too loud, it means there is something wrong. 2. Belt noise: This is usually manifested as squeaking or screaming. Belt noise may mean that the belt is worn or slack. Belt noise also occurs when a pulley on which the belt is located starts to fail. When the belt no longer moves smoothly along the pulley, the car will produce noise when accelerating. 3. Noise of exhaust system: The exhaust system includes muffler, resonator, catalytic converter and the lower pipe of the header. The exhaust system exhausts exhaust gas from the front of the car to the rear. 4. Too much carbon deposit in the engine: too much carbon deposit in the throttle will cause the engine sound to become louder. @20 19