Central to the type of hearing loss known as “sensorineural” is damage to the tiny “hair cells” that reside within the cochlea, where these sensory receptors convert sound waves into electrical signals that they transmit through the acoustic nerve to the brain. Unfortunately, once hair cells become damaged by loud noise, they do not have the ability to regenerate. As a result, hearing loss associated with hair-cell death is permanent. While sensorineural hearing loss lends itself to effective treatment with a hearing instrument, researchers continue to search for a way to regrow hair cells. Currently, two studies are underway, both of which involve injecting experimental medicines into the ear with the intention of repairing the damage that causes hearing loss.
P.S. One of the experimental drugs that researchers are hoping will regenerate hair cells is a treatment codenamed FX-322, which stimulates progenitor cells to grow into healthy hair cells.