The reason we can sometimes see things happening before hearing their corresponding sound is due to the difference in the speed of light and the speed of sound.
Light travels at an extremely high speed, approximately 299,792 kilometers per second (or about 186,282 miles per second) in a vacuum. In contrast, sound travels at a much slower speed, roughly 343 meters per second (or about 1,125 feet per second) in dry air at room temperature.
When an event occurs, such as a ball being thrown or an object falling, the light emitted or reflected from that event reaches our eyes almost instantaneously. As a result, we perceive the visual information almost immediately.
However, sound waves generated by the same event take some time to reach our ears, as they require a medium (such as air, water, or solids) to propagate. The speed of sound varies depending on the medium, temperature, and other factors. As a result, there is a delay between the visual perception and the corresponding sound reaching our ears.
The delay between sight and sound perception can be noticeable, especially when the distance between the event and the observer is significant. For example, if you see a lightning flash in the distance, the sound of thunder takes longer to reach you due to the slower speed of sound compared to light.
This phenomenon is often used in various forms of entertainment, such as fireworks displays or movies, where special effects are synchronized with sound cues to create a more engaging and realistic experience.