The origin of the megaphone can be traced back to the 6th century Greek theater. No electric voice amplifications invented so far, theater makers improvised masks with a funnel-shaped mouthpiece. As the actor spoke, his voice reverberated against the crowd and projected onto the audience. As other cultures observed and surpassed the idea, they developed the more portable versions that are still common today.
During the 19th century, theater and church enthusiasts used the inventions of Thomas Edison to further develop the traditional acoustic megaphone. By the middle of the 20th century, 1947, inventor Henry C. Dalrymple had developed and patented the first electronic voice amplification system that used a microphone and amplifier to project sound to an audience. As technology evolved and electronic components became smaller, this invention evolved into the powerful megaphones that are now common around the world.
Megaphones can be generalized into two types – acoustic and driven. While the acoustic models are based on traditional physical amplification first developed by the Greeks in the sixth century, the powerful megaphones use electrical amplification to project sound. Powered megaphones can be further categorized according to the features – possible through the use of advanced electronics – packaged in the device. Powered megaphones offer the ability to change the voice to a different sound (voice changing megaphones), broadcast music in addition to voices (musical megaphones) and produce siren sounds for use in police and entertainment functions (police megaphones).
While the alliance of units has pursued the commercial and civilian use of megaphones in virtually every conceivable use, military units are developing advanced tactical purposes for the reinforcement units. By using megaphones – specially powered megaphones – the military can direct sounds at enemy installations to induce insomnia and mental abuse.
Throughout history, megaphones have found themselves in virtually every function that requires audio transmission to a large audience. Megaphones have allowed theatrical presentations to progressively larger audiences, churches to deliver their messages to larger and larger congregations, and political candidates to pack in tens of thousands of audiences. Cheerleaders often use megaphones to move the audience at sporting events, and protesters similarly use the devices to gather support at gatherings. The police use megaphone negotiation situations, and the military actively uses them to deliver tactical psychological operations. When large crowds gather and a message must be delivered, there is a traditional tool for amplifying a human voice that goes back hundreds of years. At sporting events, political gatherings, theater presentations and protest demonstrations, megaphones are almost always a preferred method of voice amplification.