What will happen if the cinema hall ceiling is made flat?

• Curved ceilings are used in movie theatres to ensure that everyone in the audience can hear the music, dialogue, etc. such that the sound equally disperses across the entire room after reflecting off the curved surface.
• If a ceiling is flat then only the audience seated at a certain location will be able to hear the sound.

Therefore, we can say that if the cinema hall ceiling is made flat then the sound will not reach properly to every person.