Richard Rabbitt in his lab at the University of Utah



University of Utah's professor of bioengineering, Richard Rabbitt,has discovered a new way for the deaf to hear. Rabbitt used infrared light to stimulate the inner-ear cells of a toadfish and send signals to the brain. In other words, let the toadfish hear via light applied to its ear cells. The toadfish ear cells are a well-established model for comparison to human ears. The vibration of sound, gravity, and motion on inner-ear hair cells transmits the sensation/data to the brain. Rabbitt used infrared light to do the same. He elaborates, " we were stimulating the hair cells, and they dumped neurotransmitter onto the neurons that sent signals to the brain."


Rabbitt believes that infrared wavelengths work well due to the effects on the flow of calcium ions in/out of the mitichondria. Current, eletrical, cochlear implants convert sound to electrical signals via 8 electrodes. The electrical signal stimulates the nerves of the ear, and lets the user hear up to 8 frequencies. Rabbitt compares his device to current models, "A healthy adult can hear more than 3,000 different frequencies. With optical stimulation, there's a possibility of hearing hundreds or thousands of frequencies instead of eight. Perhaps someday an optical cochlear implant will allow deaf people to once again enjoy music and hear all the nuances in sound that a hearing person would enjoy."


Battery technology needs to be paired with Rabbitt's discovery before real world applications can surface. Let's hope for a speedy development.


This same effect also works with heart muscles, which may lead to innovations in pacemaker technology.


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