The renowned audiologist and inventor Mead Killion passed away comfortably on 3 November 2025 in Elkhorn, Wisconsin, US.
Mead was known for inventing products that left us scratching our heads, trying to figure out why we hadn’t thought of them first. He was a teacher who had an uncanny ability to translate complex phrases like “the acoustic impedance of the acoustic inertance is proportional to frequency” into everyday English by simply saying that “high frequencies don’t like small spaces.”
Mead C Killion.
Since the 1980s, Mead never travelled with just a single suitcase when giving talks; he also carried another bag filled with horns, lengths of tubing of various diameters, and other demonstrations that bring both the acoustics and the electronics of hearing aids to life. He carried a sound meter in his coat pocket.
And Mead never forgot his teachers. He made sure we all knew who Elmer Carlson was – an amazing engineer at Industrial Research Products/Knowles in the 1970s and early 1980s – who designed the basis for what was to become the musicians’ earplugs that Mead’s company, Etymotic Research, would develop and commercialize. Carlson’s work on the twin tube idea led to Mead’s patent on insert earphones and other ideas crucial for products that ultimately gave birth to the ER15 and ER20 musicians’ earplugs, as well as the ER3 insert earphone. Etymotic Research has made many important innovations available to our field that we couldn’t imagine not having access to. For example, the K-AMP, co-developed with Etymonic Design's Bill Cole, was one of the most successful and widely implemented hearing aid circuits of the 1990s.
And later, M.C.K. Audio was founded, which enabled Mead to develop additional products for individuals with hearing difficulties. He worked on assistive devices and numerous innovations, like a beamforming microphone array (picture a miniature boom mic) that was attached to a pair of eyeglasses. Again, way ahead of his time.
Another teacher was Edgar (Eddie) Villchur – the father of multiband compression and the modern (air-suspended) loudspeakers we all take for granted. Mead always made it clear to everyone working on his articles that his brilliant wife and partner, audiologist Gail Gudmundsen, and Eddie were significant contributors to his work and should probably be listed as co-authors. Some of his articles had an acknowledgement section that was nearly as long as the article itself! (For example, in one of my personal favourites from 1988, “An acoustically invisible hearing aid,” Mead introduced the world’s first high-fidelity hearing aid, while also acknowledging the work of many others in our field.)
Mead authored numerous papers, either solo or with colleagues: 88 articles, 21 book chapters, and he holds 92 US patents. What better way to spend an afternoon than reading through them? That is exactly what we have done. This was not just a labour of love for the editors at CanadianAudiologist.ca, but also a great way to revisit ‘first principles’ and learn from the master himself. Mead’s articles and book chapters are rich with valuable translational information. In addition to being available on the Etymotic.com website, the references can also be found on www.MeadShare.com.
In addition to me, three editors at Canadian Audiologist.ca assisted me in compiling the special issue: CA’s Associate Editor Steve Aiken and engineers Steve Armstrong and Larry Revit. They feel as privileged as I do to have called Mead Killion a friend.
Mead always encouraged others to celebrate the little things along the way. His groundbreaking work in audiology is a lasting part of his legacy, as is his commitment to making the world a better place. Contributions can be made in Mead’s memory to Wabash College, VanderCook College of Music, and the American Auditory Society.
Marshall Chasin, AuD., Editor-in-Chief, Canadian Audiologist.
The Canadian Academy of Audiology has created a special issue of its official e-journal Canadian Audiologist to celebrate Mead's life and contributions.
https://canadianaudiologist.ca/issue/volume-12-issue-6-2025/something-about-mead-2/
