Basic BackgroundThe first headphones were invented in 1919 by Nathaniel Baldwin. In 1958, jazz musician John C. Koss in 1958, invented the stereo headphones. These were intended for listeners who were eager to listen to music when they were at home, specifically individually. The headphones used before Koss’ invention, were hard to hear out of because they were made for war planes and communications. Because of Koss, music and headphones entered a world of portability in the late 1970’s.
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Mechanics behind the Headphones
With the design of the stereo headphones by Koss and other competitors, there have been great improvements with the design and mechanics behind these inventions. Most of the stereo headphones are lined with a coil and vibrating cone that converts audio wave signals into sound [1]. These stereo headphones are simply based off of a plastic structure or skeleton and then is surrounded by multiple paddings. This plastic design helps keep the weight of the headphones to a minimal [5]. Below is a breakdown of the three main mechanical forms of Koss' headphones. A description of how each headphone, electrostatic, dynamic, and enclosure works, is provided below.
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Types of Headphones
Throughout Koss' headphone development, he focused on three types of headphones. He invented and established electrostatic, dynamic, and enclosure headphones. Below are explanations and details on each of these four headphones, and the mechanics behind how they work. There is a definite distinction between each headphone.
Electrostatic
Unlike the coil concept that pushes air to the ear. The electrostatic headphones consist of a thin, electrically charged diaphragm, floating between two "perforated metal plates." These headphones are typically more expensive than the others but are known for sounding better than other headphones. The Koss ESP-9 were the first electrostatic headphones to hit the market. They can produce nine out of ten possible octaves that the human ear can hear. The Koss ESP-9 headphones were the most elaborate, complex and expensive model tested of its time. [1] [2] [6]
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The image to the left is a print ad created to describe the purpose of electroacoustics in Koss' stereo headphones. The advertisement focuses on the ESP-9, the first electrostatic headphones that Koss invented. It comments on how it has a signal capacity of 10 volts at 30 Hz. In addition it states that the electrostatics face a “push-pull balanced acoustical circuitry, canceling all second harmonic distortion to provide fatigue-free listening through long recording sessions.” The ESP-9, according to this print ad, eliminates any extra noises being the scenes, including static and heavy breathing.This is one of the few advertisements that focuses solely on the electrostatic headphones and how they work. It's important to note the science behind the headphones in order to better understand how they work. For consumers, this was the best way to do that. |
Dynamic
Dynamic headphones work very similarly like two miniature speakers. The signal is transmitted through a connection to a standard jack. In the beginning of it's invention, creating a standard jack was a long process. There were multiple jacks being created and it took a long time in order to create a standard jack that would work across all platforms. Once the electrical signal reaches the earphones from the standard jack, a magnet forces a voice coil to vibrate rapidly inside a diaphragm — a paper, fibrous or plastic cone-shaped object inside the headphones. This iteration can be seen in the image on the left. The inner works are then lifted up and down , often faster than the eye can see, creating a rapid vibration. This rapid vibration is what stirs the air and creates vibrations called sound waves which are then picked up by our eardrums [6]. This interaction between the standard jack, headphone cord, magnet and voice coil occurs to fast it's nearly impossible for us to realize what is happening; and yet we are still able to casually listen to the music and sounds we choose too.
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Enclosure
Enclosure headphones utilize sealed enclosures that have tight-fitting ear cushions that are referred to as "circumaural design."They are intended to surround your ears and rest on your head. The purpose of this is to create a "sealed air cavity" around your ears that is meant to improve the bass frequency response of headphones. In other words, it prevents the entrance of other outside sounds from entering your ears, creating a purely musical experience for your ears. This is what leads to the "orchestra-in-the-head illusion", an eerie sensation that music is originating from somewhere between your ears. The sound quality is so high that eliminates any potential outside noise, making it seem as if the noise you are listening to is coming straight from the headphones. Semi-sealed headphones designs often have foam ear cushions covered with a soft plastic. The cushions may simply rest on your ear rather than surround it. This is a form of headphone technology that has been utilized today by many modern headphone makers. The purpose is to provide a comfortable cushion that sits on your ear in order to make listening to music for hours comfortable. Even though the sound from these headphones is dismissive of outside sounds, outsiders can softly here what you're listening to. This is due to small vents on the headphones that release small small as you're listening to them. Sounds produced by these headphones “leaks out" and is audible near by. (Popular Science, 1979).
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Other Headphone Competitors
Koss' headphones had multiple competitors. However in the beginning, “Koss dominated the early part of the swinging sixties – thanks to the arrival of cheap turntables and intolerant parents - and can be blamed for the present day dirge of celebrity endorsements. (The Complete History, Dec 2013). His headphones took over the music industry, changing the way people listened to music individually forever.
Koss continued to dominate the headphone industry, despite any competitors that may have arisen. While at a Music Show in Chicago, "Koss Electronics and Shure Bros. [showed] a set of competing products, Beatlephones and Solo-Phone, which are to be used by guitarists, young and old for “quiet” practicing as well as serving a variety of other uses” (The International Music- Record Newsweekly, July 1966). Despite this competitors appearance, Koss continued to sweep the headphone industry.
Koss anticipated that there would be other competitors in the headphone industry, and began to expand upon his celebrity endorsements. This specifically occurred with the band The Beatles, when Koss invented the Beatlephones in 1966.
Just as he expected, in the1970's, Koss' headphones met its first competitor, Sennheiser and by the 1980s, Koss was no longer the dominating headphone producer. At a Consumer Electronics Show in 1980, Koss brought with him two of his headphones. He was not alone, for his competition Sennheiser appeared at the Show too, displaying open air headphones that he invented in 1968 (The International Music-Record Newsweekly, June 1974).
Koss continued to dominate the headphone industry, despite any competitors that may have arisen. While at a Music Show in Chicago, "Koss Electronics and Shure Bros. [showed] a set of competing products, Beatlephones and Solo-Phone, which are to be used by guitarists, young and old for “quiet” practicing as well as serving a variety of other uses” (The International Music- Record Newsweekly, July 1966). Despite this competitors appearance, Koss continued to sweep the headphone industry.
Koss anticipated that there would be other competitors in the headphone industry, and began to expand upon his celebrity endorsements. This specifically occurred with the band The Beatles, when Koss invented the Beatlephones in 1966.
Just as he expected, in the1970's, Koss' headphones met its first competitor, Sennheiser and by the 1980s, Koss was no longer the dominating headphone producer. At a Consumer Electronics Show in 1980, Koss brought with him two of his headphones. He was not alone, for his competition Sennheiser appeared at the Show too, displaying open air headphones that he invented in 1968 (The International Music-Record Newsweekly, June 1974).