A megaphone also referred to as a bullhorn or loudhailer is a handheld cone shaped device that can project your voice hundreds of metre away. The amplification can range in different wattages which can amplify voice up to 1000 metres . The cone shape concentrates the voice in a direction. Typical examples of megaphones would be in emergency evacuation in schools or public places, crowd control, festivals or speaking and conveying messages regarding security.