The Bionic Ear

By Dr. Joseph Skufca

For most of us, our sense of hearing is taken for granted. Certainly, we could sit in a sound proof booth and sense no sound, but we are probably unable to really imagine what it would be like to have NEVER heard sound. Our thoughts and ideas are centered around our language, which is auditory/verbal – we think in words. Although many people in the deaf community lead successful and fulfilling lives without the sense of hearing, they now have an option. Research, started in the 1950s, led to development of a device called a cochlear implant (CI) – a bionic ear which can often restore hearing sensation to people with severe or profound hearing loss.

Computed Radiography of a cochlear implant - the bionic ear.  (Photo courtesy of Radiology)  Researchers use advanced mathematics to precisely locate the implant device. [Whiting B, Bae K, Skinner M.  Cochlear implants:three-dimensional localization by means of coregistration of CT and conventional radiographs.  Radiology 2001;221:543-549].  To learn more about the mathematics of medical imaging, visit here.

The first commercial implants were available in the 1970s, with FDA approval coming in 1984. Although the initial devices were crude in capability (subjects were only able to develop limited capability to recognize a few words) the rapid advances in Digital Signal Processing (DSP) have made these implants capable of providing many users with the ability to recognize words, hold conversations, and even talk on the phone. This “miracle of modern medicine” was made possible through interdisciplinary efforts from the fields of medicine, biology, material science, bioengineering, electrical engineering, and mathematics. This installment of “Why Do Math” will focus on the mathematical underpinnings of DSP, and in particular, the mathematical miracle of the Fast Fourier Transform (FFT).

Find out more about Cochlear Implants.


About the Author

Joseph D. Skufca, Assistant Professor, Division of Mathematics and Computer Science at Clarkson University

Joseph D. Skufca is an Assistant Professor in the Division of Mathematics and Computer Science at Clarkson University, Potsdam, New York.  His research focus is dynamical systems, chaos, control, networks, and dynamics on networks.  His B.S. degree is from the United States Naval Academy (1985).  He served as a submarine officer in the United States Navy before retiring in 2005.  He earned his PhD in Applied Mathematics from University of Maryland, College Park.  His daughter, Julianna, received a cochlear implant in 2004.