Egbert de Boer

Egbert de Boer passed away on 12 August 2022 at the age of 94 years. He was a passionate and highly talented researcher, a committed audiologist, an excellent teacher, and an amiable colleague.

Egbert performed his early scientific work at the Wilhelmina Hospital in Amsterdam. Under the direction of his mentor, Leonard Jongkees, he did psychophysical experiments on pitch as well as electrophysiological experiments on distortion products in animals. He received his PhD in 1956. His thesis was titled “On the ‘residue’ in hearing.” He went to work in a hospital clinic that led to an active interest in hearing loss. He became an audiologist of both the school for the hard-of-hearing and the school for the deaf.

In 1957 Egbert attained important postdoctoral experience working in Walter Rosenblith’s group in “communication biophysics” at MIT. There he was appointed instructor in the department of physics, where he taught electronic circuit theory and information theory (subjects he admitted to not being an expert in at that time). None other than Nelson Kiang and Jerry Lettvin introduced him to cochlear electro-physiology.

Upon return to Amsterdam, Egbert resumed work in the ENT clinic to do audiology and research on hearing and balance. He became interested in mathematical correlation and correlation functions, which eventually lead to his seminal paper on “reverse correlation.” When applied to the analysis of auditory neuron responses, the method showed that the cochlea behaves like a series of location-dependent filters . As he climbed the academic appointments ladder to professor of auditory physics, Egbert investigated the critical bandwidth. Another visit to the US brought him to Bell Labs, where he worked in the laboratory of Manfred Schroeder on nonlinear systems.

Egbert made a move to the Academic Medical Center in 1982. Throughout his career there, he worked on cochlear mechanics as a theoretical endeavor, leading to the lifelong publication of more than 170 papers. He was a founder of the Mechanics of Hearing Workshop. Retirement in 1996 opened the opportunity to analyze cochlear mechanics experimental data that he collected himself. This was accomplished by regular visits to the laboratory of Fred Nuttall, first at the Kresge Hearing Research Institute of the University of Michigan and then at the Oregon Hearing Research Center at the Oregon Health & Science University. The postretirement part of his career resulted in nearly 50 of his total publications—a truly remarkable career achievement.

As an audiologist, he was associated with various schools for the hard of hearing and the deaf and saw the opportunity to achieve the utmost for the students of these schools. Thanks to his didactic gifts, he also stimulated much innovation in clinical audiology. On his retirement he was appointed as a member of Merit of the Dutch Association of Audiology.

His postretirement work was central to the symposium that Egbert presented in 2008 in honor of his 80th birthday. And in 2013 he was awarded the William and Christine Hartmann Prize in Auditory Neuroscience for his outstanding research achievements, an international recognition of his contribution to science and a special honor, especially at this advanced age.

Besides being a very good skater, Egbert ran the Amsterdam Marathon after his “retirement” at the age of 79, and he played the piano very creditably all his life. He also studied Italian for many years. He was a watercolor painter, a student of Haiku, and a composer of classical music. Perhaps he qualifies as a polymath, and we remember him as versatile and committed, an inspiring person, and a dear friend.