Microphone Evolution Timeline: A Breakdown of Microphone Developments
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With mics deeply embedded in our daily lives, it’s nice to appreciate and be knowledgeable of the notable microphone developments through the years. From the earliest known microphone being as big as a speaking horn to now fitting inside our pockets, microphone technology, design, and applications have developed in more ways than one.
In this article, we break down a chronological timeline of noteworthy microphone developments and see how they have helped in evolving the different microphone types and sound quality we have today.
What is the Early History of Microphones?
The term “microphone” was first coined back in 1827 by Sir Charles Wheatstone. The English physicist was the man behind the first telegraph. It was through this invention he was able to create devices that could amplify sound while transmitting it to another location. He was also one of the first scientists to discover that sound can be transmitted through waves within a medium.
However, the “formal” history of microphones dates back to 1861 and is attributed to Johann Philipp Reis. The German inventor was the man behind the Reis telephone — a device that was able to convert sound into electrical signals.
In today’s time, the Reis telephone is what we would define as a transducer that can convert mechanical wave energy (sound waves) into electrical energy (audio signal). This was achieved by how Reis designed the telephone; made of a horizontally stretched parchment diaphragm which he mounted on top of a closed wooden box. To allow sound to enter, he also placed a big speaking horn.
Inside the telephone were two brass strips. One strip was attached to the center of the diaphragm while the other was mounted above it. This design caused sound waves to make the parchment diaphragm vibrate while the resistance between the contacts would change proportionately. In effect, the sound vibrations would send an electrical signal through the speaker.
Thus, Reis’ invention was pivotal in the formal invention of the microphone later on and became a prototype of the core microphone design.
When Was the Microphone Invented?
The invention of the first microphone is arguably debatable. Due to patent rights and court rulings, Thomas Edison was legally the inventor of the microphone. However, it was Emile Berliner who invented the first microphone in 1876 alongside Thomas Edison.
After the collaboration between Berliner and Edison, the microphone was formally introduced in 1877. David E. Hughes would later on independently create the same type of carbon microphone in 1878. In the same year, Alexander Graham Bell bought the patent for Berliner’s microphone, which would later on be sold to Thomas Edison for an amount of $50,000. Thus, the Supreme Court ruled in 1892 that Edison was the inventor of the microphone.
What is the Oldest Type of Microphone?
The oldest known type of microphone is the carbon microphone of Emile Berliner and Thomas Edison. Berliner and Edison’s invention was a drum-like device that consisted of a carbon button microphone, which they would also call the microphone a “loose-contact transmitter” as it had two electric contacts separated by a layer of carbon. When joined together with the diaphragm, the electric contacts would vibrate upon getting struck by a sound wave.
What is the History of Microphone Development?
The history of microphone development is rich and busy. With plenty of inventors and scientists contributing to the evolution and advancement of microphones, many microphone types were created and applications of the recording device broadened. Let’s take a look at some key milestones in the history of microphones.
1861: Reis Telephone
German invention Johann Philipp Reis designed and built the Reis Telephone. While he makes use of the term ‘telephone’, it is arguably the device that paved the way for the design and prototype of the microphone today. The Reis Telephone was a transducer that converts mechanical wave energy into electrical energy, which is essentially how microphones work.
1876: Liquid Transmitter
The liquid transmitter or water microphone was part of Alexander Graham Bell’s telephone invention. It became pivotal in the development of microphones as it was more effective in reproducing intelligible speech than its predecessor.
The liquid transmitter differed from the Reis Telephone as it was made from a metal cup filled with water and small amounts of sulphuric acid. The addition of the acid helped in making the liquid electrically conductive. Aside from this, the liquid transmitter had a diaphragm that was stretched into a small horn and attached to a needle. The other end of the needle was also submerged in the liquid but this did not touch the metal cup.
As a result, when the needle vibrates in the water, the water resistance fluctuates. The design of Alexander Graham Bell helped create an inversely proportional electrical signal to the telephone or liquid transmitter’s speaker.
1876: Carbon Microphone
As Alexander Graham Bell created his liquid transmitter, Thomas Edison took down notes for his development of the first carbon microphone in the same year. Additionally, the carbon microphone is the first microphone in history.
Although there were prior microphone-like inventions such as vacuum tubes, Reis Telephone, and the Liquid Transmitter, the carbon microphone was different in design, technology, and quality. This was the first microphone that used two metal plates and separated them with carbon granules to cause a changing electrical resistance. In essence, the carbon microphone became a variable resistance device that turned sound waves into electrical audio signals.
During this time, the carbon microphone worked by having one plate thicker and stationary while the other plate was thin and used as a diaphragm. The sound pressure or sound waves will cause the diaphragm to vibrate and produce pressure on the carbon granules. With that, a change in electrical resistance will occur between plates and a steady DC voltage will be applied.
With this improved design and technology, the carbon microphone was able to produce high-level audio signals and became more practical. Thus, carbon microphones were widely used in telephone systems.
1877: Moving-Coil Microphone
For as early as 1877, the moving-coil microphone already existed thanks to Ernst Werner Von Siemens. He designed the first practical moving-coil microphone using a diaphragm and attached it with a moving coil within a permanent magnetic field. Whenever the diaphragm and coil move, a small electrical current will be induced across them.
While Siemen’s invention of the moving-coil microphone became important for the creation of future microphone types, his early design did not gain much popularity when it was made public.
1886: Carbon-Button Microphone
Thomas Edison sought to further improve on the carbon microphone and the liquid transmitter (Bell Telephone Microphone), and he was successful in doing so. Edison invented the carbon-button microphone wherein he roasted the carbon of the initial design and combined it with structural improvements. Carbon microphones would be used in all Bell telephones until the 1980s.
Later on, Western Electric would develop the famed double-button carbon microphone that would be widely used in the “candlestick” telephone.
1916: Condenser Microphone
American physicist, Edward Christopher Wente, invented the first condenser microphone in 1916 while working in Western Electric. Taking inspiration from its predecessor, the carbon microphones, Wente’s condenser microphone made use of two plates. However, he thought of adding a space between the plates rather than placing carbon granules.
This change caused the two plates to act as a capacitor and a consistent voltage gave the microphone a fixed charge, which allowed the diaphragm of the condenser microphone to coincide with the AC voltage that would be outputted from the mic.
With that said, the condenser mic is also called a capacitor microphone or electrostatic mic. Through Wente’s design, the condenser microphone will later become one of the two main microphone transducer types in the market.
1917: Piezoelectric Microphone
The invention of the piezoelectric microphone or crystal microphone can be attributed to two people: Paul Langevin and Alexander Nicolson. While you might think they worked together to create the piezoelectric microphone, that is not the case.
Paul Langevin was the first person to use piezoelectric crystals to detect sound. From here, he created a device that will be used as an ultrasonic submarine detector and ultrasound frequency emitter. At the time, Langevin’s invention was initially used to help calculate the distance of enemy submarines as the amount of time it took for the signals to travel back to the source would show it. Additionally, Langevin used an electrostatic condenser microphone to help create his device.
Two years later, Alexander Nicolson formally invented the piezoelectric microphone, or crystal microphone that is capable of capturing sound waves. With this, the development of crystal microphones, piezoelectric loudspeakers, and phonograph pickups was also made possible. All these would later on pave the way to the invention and development of electret microphones and contact microphones.
1920: Electret Microphone
While plenty would claim that the electret microphone was invented in the 1960s, the first one was created by Japanese scientist Yoguchi in 1920.
Yoguchi’s electret microphone used similar elements and designs to the early condenser microphone. However, the backplate of this ‘primitive’ electret microphone made use of an electret material to help hold the fixed charge across the plates.
While this early electret condenser microphone was not capable of sustaining charges for long, Yoguchi played a huge role in future designs and technology of electret condenser microphones.
1924: Ribbon Microphone
German scientists Walter Hans Schottky and Dr. Erwin Gerlach co-invented the first ribbon microphone. The ribbon microphone that the two scientists invented was a dynamic microphone that works on electromagnetism.
Similar to most ribbon microphones today and to moving-coil microphones, Schotkky and Gerlach’s design for their ribbon dynamic microphone is to suspend a thin aluminum ribbon within a magnetic structure. The ribbon was used as a replacement for the diaphragm element that was mostly used in condenser microphones at the time. As a result, the ribbon dynamic microphone had a conductive ribbon that allowed it to generate an AC voltage or audio signal.
However, the ribbon dynamic microphone design of Schottky and Gerlach did not have strong enough magnets that make this mic practical for audio production applications at the time. However, their design already proved to outperform ancient condenser mics in quality and frequency response.
It was in 1930 when Harry F. Olson improved the ribbon microphone design and technology for this sensitive dynamic microphone to make it more practical. The ribbon microphone was so greatly developed that it became a favored recording device in the radio broadcasting industry.
1931: Moving-Coil Dynamic Microphone
While dynamic microphones were arguably invented in 1877 by Ernst Wener von Siemens and later further developed by Henry Joseph Round in 1923, the modern moving-coil dynamic microphone was developed in 1931.
This moving-coil microphone was invented by Edward C. Wente and Albert L. Thuras of Western Electric using a circular polystyrene diaphragm that has a conductive coil attached to the rear sides and stronger magnets. With the newly developed microphone technology, the moving-coil microphone produced audio signals across the coil via electromagnetic induction stronger than previously developed microphones.
1941: Line “Shotgun” Microphone
Harry F. Olson of RCA, the engineer and inventor who helped develop and improve on the ribbon microphone design, invented yet another microphone — the line “shotgun” microphone.
Olson was awarded a US patent for an “electro-acoustical apparatus” otherwise known as the line microphone. With this patent, he was able to measure and create slots on an interference tube that would allow sound to enter and pass through until the far end. With such a design, shotgun microphones produced a focused sound depending on where the tube was pointed at hence, “shotgun”.
The development of the top-address unidirectional microphone, analog devices, and mics with varying polar patterns allowed shotgun mics to further zone in on a sound.
1948: Multi-Pattern Microphone
Not long after, the multi-pattern microphone was invented by Georg Neumann and his engineers at Georg Neumann GmbH. This was made possible due to their creation of the M7 dual-diaphragm condenser microphone capsule.
Although it was in 1928 when Neumann and Co. created the first commercial condenser microphone, it was this Neumann U 47 tube condenser microphone with the M7 dual-diaphragm condenser capsule that catapulted the development of microphones further. This was the start of condenser mics that would feature varying polar patterns as the Neumann U 47 multi-pattern microphone proved that a single device can become an omnidirectional microphone and a cardioid microphone at once.
1957: Wireless Microphone
While the idea and design for the wireless microphone date back to the mid-1940s, the first recorded patent for the wireless microphone system was in 1957. This patent was filed by Raymond Litke, and he later was credited as the inventor of the wireless microphone.
He intended the wireless microphone to be used in applications such as television, radio, and education. With this in mind, he designed two wireless microphones: the handheld wireless mic and a miniature Lavalier.
1959: Top-Address Unidirectional Microphone
An engineer from one of the famed and top microphone manufacturers invented the first top-address unidirectional microphone to the market in 1959. This engineer is named Ernie Seeler and he developed the Unidyne III capsule while he was in Shure. Later on, the microphone will be sold to the public as Model 545.
What made Seeler’s invention important to the development of microphones is it allowed the capsules of mic to be placed at the end of a mic (on top to be exact) rather them be side-addressed. This allowed the microphone to be less susceptible to audio vibrations in the air and other noise coming from the sides.
1961: Electret Condenser Microphone
The Bell Laboratories greatly contributed to the development of microphones in history. Among its long list of contributions is the electret condenser microphone in 1961 by engineers Gerhard Sessler and Dr. James E. West.
Although the electrostatic microphone was invented earlier on by the engineer also from Bell Laboratories, the electret condenser microphone made use of a more practical yet advanced technology that allowed these mics to be manufactured at a lower cost. The electret condenser microphone thus became one of the most common types of to be used by the market because of its high input impedance and high impedance circuit. Such development would pave the way for the MEMS microphone and digital microphone.
1965: Solid-State Condenser Microphone
Around this time, the vacuum tube was slowly getting phased out due to the invention of the transistor. Inventors, engineers, and manufacturers saw that using FETs was not only cheaper but also longer-lasting than its predecessor, making it more practical to use in microphones. Such is the case that Schoeps developed a solid-state condenser microphone. This invention led to the creation of a wide range of RF condenser microphones.
1983: MEMS Microphone
The MEMS microphone is based on silicon micro-machining and was developed by D. Hohm and Gerhard M. Sessler. The two looked at the electret microphone of Sessler for inspiration and developed the Micro-Electro-Mechanical System technology.
With improved technology and design, MEMS microphones are becoming more preferred by many in the industry nowadays. Unlike capacitor microphones and electrets, MEMS mics are smaller in size, have lower sensitivity to mechanical shocks, have integrated CMOS electronics, and can withstand high-temperature PCB mounting processes.
2003-Present: Digital Microphone
Although digital audio has been constantly developed since the 1960s, it was in 2003 when digital mics made a breakthrough. With engineers at Georg Neumann inventing the first-ever digital microphone, D-01, the industry and public market were blown away at the capabilities of these recording devices.
With a built-in analog-to-digital converter that allows the microphone to output audio, digital software, and mic technology that can make devices adaptable and versatile, the potential of microphones has never been greater.
Since then, manufacturers and audio industries have strived to make better digital microphones than the latest model. While certain features outperform each model from the previous one, digital microphones all work essentially the same. Taking inspiration and learning from all the past developments, digital mics made use of an internal analog-to-digital signal converter to produce sound.
Final Note
As manufacturers and companies continue to develop microphones to meet the demands and changing standards of the industry, it’s nice to know how these recording devices came to be in the first place. A lot can be learned from its history and one can imagine what the next development and breakthrough might be. This is why we see many categories for microphones coming to fruition as improvements and developments for niche categories such as vocal mics, studio mics, and more are becoming more advanced and specific for applications.
