The Explanation History of Loud Speaking and The Loud Speakers

Every time I attempt to go deep into the forest, I hear the warning chorus of monkeys and chimpanzees sitting on the tree tops. They might be doing this since some 30 million ago. At that time, the dry-nosed Haplorrhini were transforming themselves into the downward-nosed Catarrhini and Hominoidea family of gorillas, chimpanzees and humans. We can visualize the timeline of loud speaking and the loudspeakers.

Some 2.5 million ago, the earliest homo sapiens left their fossil evidence on the Earth thus authenticating their existence. At that time, our ancestors must have heard loud sounds coming from nowhere or from the sky. It could be thunder of clouds. We find references to certain thundering celestial voices. The Hindu mythological stories call it the voice of God. Such references of "divine voices" could be found in almost all the religious books and epic tales.
Perhaps such a sound prompted the early man to convey messages from the top of the hills or trees so that the same reaches to distant places. Later, conical trumpets made from the bark of the trees and bull horns amplified the human voice much more.
To this day, we find a cone-shaped hand-held megaphone or a bullhorn to amplify and direct the voice. Electric powered megaphone became visible sometime in 1970s.
The name "loudspeaker" refer to the transducers ( called driver) or more drivers in a complete system that reproduce an extensive range of frequencies. These drivers are known by their range of frequency. Tweeters handle high frequencies. Woofers control low frequencies. Subwoofers manage very low frequencies.
The moving coil type driver was patented in 1924. These loudspeakers used electromagnets. Since then, there has been several changes and improvements. Permanent magnets are made of ferrite, alnico, ceramic and rare earth. The cellulose paper used in making cones are doped with a superior stiffening and damping material such as carbon fiber, Kevlar or bamboo fibers. The adhesive used can withstand high temperature. With the aid of CAD (computer aided design), latest measurement techniques and finite element analysis, we have now far superior speakers.
These days, there is a distinctive leaning towards small gadgets. There are speakers as small as a button. Some look like decorative pieces. Most of these mini speakers are compatible with the latest electronic gadgets such as iPod, iPhone and laptops.

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