What communication method is often used for large or loud construction sites?

The correct choice focuses on the use of visual signals and flags, which are essential in environments where sound may be drowned out by heavy machinery and other loud operations typical of construction sites. In such noisy settings, relying solely on verbal communication is not effective, as it can lead to misunderstandings and safety risks.

Visual signals, such as flags, play a critical role in conveying commands and information over distances and amidst distractions. They provide a clear, immediate way for signal persons and equipment operators to communicate without the need for verbal exchanges that might not be heard. This method ensures that instructions are delivered effectively, promoting safety and coordination among workers.

The other options may not effectively address the challenges presented by a noisy construction environment. Relying only on verbal communication or hand signals could lead to critical misunderstandings, while outright rejecting the possibility of communication due to noise overlooks established methods that enhance safety and operational efficiency.