Can someone help me with megaphone?

A megaphone is a portable, usually hand-held, funnel-shaped device whose application is to send a person’s natural voice toward a targeted direction for a specified purpose. This is accomplished by channeling the sound through a funnel. The natural human voice tends to spread evenly in all directions, whereas when it is sent through a megaphone, the sound is concentrated in a given direction. The trade-off is that if a listener is to the side, it is more difficult to hear what is being said. Famed inventor Thomas Edison exhibited an early version of the megaphone at the Paris Exposition in 1878.