Since ancient times, sound and light have served people to transmit messages over long distances
At the beginning of its development, a person, warning his fellow tribesmen about danger or calling for hunting, gave signals by shouting or knocking. Sound is the basis of our speech communication. But if the distance between the interlocutors is large and the voice strength is not enough, auxiliary tools are required.
So man began to use whistles, animal horns, torches, bonfires, drums, gongs, and after the invention of gunpowder-shots and rockets
Since ancient times, sound and light have served people to transmit messages over long distances
At the beginning of its development, a person, warning his fellow tribesmen about danger or calling for hunting, gave signals by shouting or knocking. Sound is the basis of our speech communication. But if the distance between the interlocutors is large and the voice strength is not enough, auxiliary tools are required.
So man began to use whistles, animal horns, torches, bonfires, drums, gongs, and after the invention of gunpowder-shots and rockets