Synonyms for the word bullhorn include megaphone, loudhailer, speaking trumpet, and voice amplifier. A megaphone is a handheld or shoulder-mounted cone-shaped device that amplifies sound. A loudhailer is a device that amplifies sound through a speaker or a cone-shaped horn. A speaking trumpet is a device used for communication on ships and boats, which amplifies sound through a narrow tube-shaped horn. A voice amplifier is a device worn on the throat or held in the hand to enhance the user's voice. These synonyms are often used interchangeably, but they all refer to devices used to amplify the voice and make it louder and clearer.