The science behind hearing loss
The cochlea in our inner ear contains 15,000 tiny, hair-like structures called “stereocilia”, or hair cells. There are two types: auditory and vestibular, responsible for hearing and balance respectively. Auditory hair cells function by bending in response to sound, and their movements are transmitted as electrical signals to the brain, which interprets them as sound. When these hair cells are damaged or killed, it can cause permanent hearing loss—and although hearing aids can be used as a kind of “hearing band-aid”, the cells cannot be regenerated. Birds and many amphibians have the natural ability to recover their hearing by regenerating hair cells, and researchers are currently studying them in hopes of artificially mimicking their regeneration process. They have also recently found that the zebrafish uses hair cells on its body to sense its surroundings, and these work in similar ways to humans’, presenting an opportunity for experimentation to screen helpful chemicals and treatments. Researchers have managed to identify protective chemicals by dyeing the fish’s hair cells, administering the chemicals, then exposing the fish to another chemical known to kill hair cells. The surviving hairs remain dyed, signifying that the protective chemical worked. These chemicals are now being tested on rodents, but there’s been no human testing yet, and it’s estimated that a cure for hearing loss is still 20 years away.
Read more about the research of zebrafish