https://www.studiobinder.com/blog/what-is-sound-design-for-film/

Sound design is an extremely important part of the film as a carrier. It can portray the characters, and can also highlight the atmosphere brought to the audience at different stages and different plots, and bring stimulation from the sound. In my understanding, film sound design requires enough knowledge of the film and the corresponding cultural knowledge to maximise the display of the characteristics of a plot or character. This is especially important and valuable. Good sound design can make a short film even more powerful, so film sound design involves the fantasy of space and the description of delicate parts.