An emergency voice/alarm communications system uses which type of communications?

• A. Two way
• B. Bi-directional
• C. Multi-way
• D. One way

Answer: (D)

The key idea is that emergency voice/alarm systems are primarily built to broadcast instructions to all occupants, not to carry back-and-forth conversations. In an emergency, you want fast, clear, unified messages delivered from the control panel to the building’s speakers, so everyone hears the same directions and can act quickly. That makes it a one-way communication system by design—messages flow from the central system to the occupants, without requiring a reply or interactive channel that could complicate or slow things down.

Using two-way or bi-directional communication would introduce microphones, back channels, and potential interference, which isn’t necessary for delivering urgent evacuation instructions. Multi-way adds even more complexity without adding essential value for disseminating critical guidance. So, one-way communications best fit the goal of rapid, reliable occupant notification.