A Brief History of the Bionic Ear
Mankind has spent centuries in pursuit of various means by which to alleviate deafness but the most incredible development in this long history simply has to be the bionic ear. The term will be familiar to many who were fans of the ‘70s television series – ‘The Six Million Dollar Man’. The hero, played by Lee Majors, was extensively injured in a test flight and was rebuilt using robotic body parts that included one which enabled him to detect faint sounds over great distances. In the current context, the term actually refers to a device which, though certainly no less amazing than its fictional version, is more accurately described as a cochlear implant or CI.
The first simple step in the quest to develop this type of device can probably be attributed to a pair of Anglo-Indian surgeons who, in the early ‘50s, applied a current to wires placed in contact with a patient’s auditory nerve during surgery. The procedure successfully induced a sensation that was audible to the patient who later described it as similar to the sound of a cricket or a roulette wheel.
Several years later, during 1957 to 1958, a series of experiments by a second team led to the sub dermal implantation of a miniature device with no physical connection to the external environment. It contained a pair of coils that were able to produce unprocessed sounds in response to a wireless signal generated externally. The device was prone to mechanical failure and did not produce coherent speech but patients remarked that it made lip-reading easier by duplicating the rhythm of speech – a significant advance in the history of the bionic ear.
Just 3 years later in 1961, the efforts of one Dr William House with single and multichannel prototypes included attempts at speech modulation using a carrier wave. It was the advance that led to him being widely acknowledged as the inventor of the cochlear implant and was the basis for development that over the next 20 years saw over a thousand patients and the first commercial unit to receive the approval of the FDA in 1984.
Since then, further technological advances have resulted in huge improvements in the performance of these implants. The successful miniaturization of the components of these systems that must be worn externally has also served to make their use more socially acceptable.
It is important to stress that, unlike a conventional hearing aid; these units do not simply act to amplify sounds to the point where they can be heard by the user. In fact, they are designed for use by those patients who have suffered damage to the hair-like, sensory cells in the cochlea and for whom mere amplification can offer no benefit. Instead, they provide an alternative means of converting vibrations into electrical impulses. These are not perceived by the brain directly as normal speech but, with the appropriate training, users who were once profoundly deaf are enabled to understand speech and other environmental noises.
The Ear Institute operates specialised audiology clinics with extensive experience of cochlear implantation devices and their applicability. Following diagnosis and confirmation of suitability the clinics are able to supply state-of-the-art units and the necessary follow-up support – adding another page to the history of the bionic ear.