Why is it important to record a few seconds of silence, known as 'room tone,' at a filming location, even when no one is talking?

Recording a few seconds of silence, known as 'room tone,' at a filming location is essential because every environment possesses a unique, low-level ambient sound profile, or 'noise floor,' even when no one is speaking. This noise floor consists of subtle, inherent sounds like distant traffic, a building's ventilation system, or the natural acoustics of the space itself, which collectively def....