James West and Gerhard Sessler: Electret microphone


Whenever you pick up a phone headset, dial a number and start speaking, you should think of Bell Labs inventors James West and Gerhard Sessler.

Gerhard Sessler and James West

Sessler, left, and West, right (Image sources: Darmstadt University / Princeton University)

Although electret materials were known as early as the 1920s for microphone use, West and Sessler designed one that used a thin metalized Telfon foil. After the design was finalized in 1962 at Bell Labs, the electret microphone went into widescale production in 1968.

Just how big was the electret microphone invention? Consider this: almost 90 percent of the over 2 billion microphones created every year for various devices such as telephones, camcorders, and audio recording devices are based on the foil-electret concept.

While Sessler and West would both eventually leave Bell Labs after long careers, the two men continue to carry on their innovative spirit in the academic world.

Sessler spent 25 years as a professor of electrical engineering at Darmstadt University of Technology. Eight years into his tenure at the university, he invented the silicon microphone in 1983. Today, Sessler is Professor Emeritus at Darmstadt University of Technology and continues to conduct active research.

During his 53-year career as a scientist and researcher, Sessler served as both an author and editor of various books on electrets and acoustics and has published over 300 scientific papers in a number of high profile scientific journals.

Likewise, West left Lucent Technologies following a 40-year career at Bell Labs. He took a research professor post at the Whiting School at Johns Hopkins University, in the Department of Electrical and Computer Engineering. At the time he left Bell Labs in 1997, West held over 47 U.S. patents and over 200 foreign patents.

Besides his contributions to the communications industry, West was a pioneer in driving diversity at Bell Labs and in the overall science community. During the 1970s, he became a member of the Association of Black Laboratories Employees (ABLE) at Bell Labs that influenced management to fund the Summer Research Program (SRP) and Cooperate Research Fellowship Program (CRFP). These programs helped over 500 non-white students graduate with degrees in science, engineering and mathematics.