The role of the Utah Artificial Ear project in the development of the modern cochlear implant

The cochlear implant has provided the first substantial restoration of a human sense by a medical intervention. This accomplishment was brought about by the efforts, over a 50+ year period, of many individuals in laboratories around the world. In this paper, we recount the history of one of the early projects - the Utah Artificial Ear project. In 1970 researchers at the University of Utah began work on an auditory prosthesis. A critical early decision was to create a 'transparent' link between external signal processing and the electrodes implanted in the cochlea, i.e., a percutaneous pedestal. The pedestal allowed D. Eddington, then a graduate student, to conduct, in 1975-1978, the first thorough, parametric, psychophysical studies of electrical stimulation of the cochlea in multiple human volunteers. The early work by Eddington and colleagues evolved in 1983 into the 4-channel, Ineraid cochlear implant. Many years later, highly effective, modern signal processing algorithms, e.g., continuous interleaved sampling (CIS), fine structure processing (FSP), and virtual channel processing, were first tested and developed with the aid of Ineraid patients fit with pedestals of the Utah design. Because for many years the Ineraid provided as high a level of speech understanding as that provided by other devices and because the percutaneous pedestal allowed the first testing of many modern signal processing algorithms, the Utah Artificial Ear project may be viewed as one of the most valuable research projects in the history of cochlear implants.