Megaphone. It is a portable, handheld device used to amplify a person's voice.
Megaphones are often used for announcements, crowd control, and giving instructions in large or noisy areas.
Modern megaphones are electronic and typically include a microphone, an amplifier, and a speaker.
Many models come with additional features such as a built-in siren, volume control, and a recording function for playing back messages.
They are used in various settings, including sports events, political rallies, and emergency situations.