Neurologists have discovered that by minimizing eyesight and causing temporary blindness for one week, hearing loss can be reversed. The brain is altered within the short time-frame and compensates for the hindered sense of sight.
Hey-Kyoung Lee is an assistant professor at John Hopkins University. She paired up with Dr. Patrick Kanold, a biologist at the University of Maryland, to conduct research on how hearing is effected by limiting sight. The results of the experiment, funded in part by the National Institute of Health, were published in the journal Neuron.
Mice were used to determine a brain connection linking blindness with improved hearing. Researchers simulated blindness in the mice by placing them in a darkened environment for a week. They recorded their response to various sounds and compared them to the results of mice who acted normally and were not limited in vision.
They found that limiting their eyesight provided the ability for the mice to hear more accurately. By temporarily blinding the mice in the study, their hearing improved and they were able to pick up different pitches. Lee describes the experience by comparing it to people listening to a familiar song along with noise in the background. The loud noises would alter the sound of the song, drowning out some of the notes.
Her work with the mice provides evidence that when the sense of hearing is enhanced by reducing another sense, sound comes through with a whole new level of clarity. For people, it would mean being able to pick up those missing notes. “People can actually hear better if they can’t see,” she said.
They essentially proved the age-old theory that if one sense is impaired, the other senses are enhanced. The senses do not work in isolation, but as a group of connected senses, which are regulated by the brain. Reactivating connectors through the brain is key to reversing damage and enhancing the senses. Dr. Kanold suggests that while it is more difficult to alter brain reactions in older adults, similar results are likely to occur if humans were placed in the same experiment. It is unclear how long people would need to be restricted from light to get restore hearing, however.
Researchers also noted that once the mice were returned to a normally lit environment after being temporarily blinded, they only experienced improved hearing for several weeks. As the five-year study continues, they hope to find a way to permanently reverse the hearing loss. Furthermore, it may be used in the future to treat people who have experienced hearing loss on a deeper level.
Dr. Kanold states that they simply strengthened the auditory cortex connections. The results of the experiment shows that people with cochlear implants could have better success and improve their sense of hearing though temporary blindness. People who have never been able to hear may experience sound for the first time by altering their auditory connections. Additional testing is expected to confirm their belief that the reverse is also true and if they restrict hearing, they would notice an improvement in eyesight.
By Tracy Rose