Megaphone, << MEHG uh fohn, >> is a hollow, cone-shaped device used to make a voice sound louder. A person speaks or shouts into the small opening at one end of the megaphone, and the sound of the voice comes out at the wide end. The megaphone makes the voice sound louder by pointing sound waves in one direction and reducing the spreading of the waves in other directions. Megaphones vary in size, and some are over 2 feet (61 centimeters) long. Cheerleaders often use megaphones during their routines so that spectators can hear them. A portable, battery-powered megaphone that combines a microphone, an amplifier, and a loudspeaker is called a bullhorn.
