What would happen if there was no sound in the world? Let’s talk about it based on physics knowledge

People hear all kinds of sounds every day, including birds chirping, voices, car horns...

If there were no sounds in the world, people would speak dumbly. Conversation, that time...

One morning, I was walking out of the house to go to school, and a miracle happened! People on the streets are doing all kinds of strange movements with their hands. Huh? Isn't this what I was thinking about last night? I didn't quite believe this was reality, so I continued walking forward and saw something even more unbelievable: a car hit another car because it couldn't honk its horn. Another amazing thing happened: the teacher was holding the pointer while speaking silently to the classmates with both hands, and the pointer fell off with a "plop"! I couldn't believe it anymore, I bit my arm, hey! It turned out to be a dream!