megaphones

A megaphone, also known as a bullhorn, is a device used to project and amplify a voice so it can be heard over a greater distance. Traditional megaphones work purely by acoustic amplification, while many modern devices include electronic amplification.

A typical non-electronic megaphone consists of a conical horn with a narrow mouth and a wide mouthpiece. The user's voice is directed into the narrow end and is amplified as it travels through the horn, focusing energy in a forward direction and reducing lateral dispersion. Materials are plastic or metal; sizes vary from small handheld units to larger coaching horns.

Electronic megaphones add a microphone, an amplifier, and a loudspeaker powered by batteries. They may feature adjustable volume, siren or voice-activation, and sometimes playback of recorded messages. They extend range and intelligibility in noisy or large environments.

The concept derives from the speaking trumpet used by orators, sailors, and officials in the 17th–19th centuries. The term megaphone combines Greek mega, large, and phone, voice or sound. Electronic megaphones appeared in the early to mid-20th century and became common for public events, sports, and emergency communications.

Megaphones are used in demonstrations, sports events, tour guiding, safety drills, and crowd control where portable amplification is needed. Limitations include wind and distance, potential distortion at high levels, and noise regulations or hearing risk; proper use and moderation are advised.