Whether you have no idea what it is in our Pink Megaphone Sticker - this is a megaphone, a device used to amplify sound and increase its volume. It is also known as a bullhorn or loudhailer. The basic design of a megaphone is a cone-shaped horn, which narrows at one end and flares out at the other. The narrow end is held up to the speaker's mouth, while the wide end projects the amplified sound outward to a larger audience.