I’ve written often here about the remarkable ways shellfish have altered the course of human history. So I was intrigued to see a recent interview about how a shell inspired the invention of cochlear implants. It appears in the Aussie magazine Cosmos, where I am an occasional contributor. Here’s an excerpt:
During one Melbourne summer in 1977, he took his young children to the beach to escape the heat. While they were playing in the shallows, Clark noticed a seashell lying on the ground – and that its helical structure was a crude replica of the human cochlea.
Inspiration hit. He pulled up some grass blades and experimented with teasing them into the shell’s opening. Owing to their flexible tips and stiff bases, the blades slid smoothly into the tightening spiral. It revealed a simple solution to a complex problem.
Rushing back to the lab, he confirmed that wire electrodes following the same design as a grass blade would solve his problem. Designed with progressive stiffness, the electrodes could be made to travel the length of the cochlea, all the way to the nerve cells that code for speech.
This design is now the basis of the hugely successful cochlear implant, a small surgical implant that simulates hearing for the deaf by stimulation of the auditory nerve to reproduce speech. Today, more than 200,000 people have received cochlear implants in more than 100 countries.
Here are some other interesting examples of human interactions with shells. They’re excerpts from a story I wrote for Smithsonian Magazine about shell madness, parts one, two, three, four, and five. Better yet, check out chapter four, “Mad About Shells,” in my new book The Species Seekers: Heroes, Fools, and the Mad Pursuit of Life on Earth (W.W. Norton, November 1).
strange behaviors 