Hearing loss is a growing epidemic: it is estimated that one billion people worldwide will experience hearing loss at some time in their lives. In order to find a solution to this problem, technology has been advancing in the field of audiology with hearing aids, cochlear implants and other devices to assist with hearing loss after it has already happened. These devices merely mimic the hearing process, however, and doctors have been powerless to cure or reverse hearing loss.
We know that progressive hearing loss is usually caused by a loss of hair cells in the inner ear. These hair cells allow us to detect sound. Humans are unable to re-grow these cells once they are damaged or lost, but some bird and fish species can. Scientists are now pursuing the theory that if humans can regrow these inner ear hair cells, hearing loss may be reversed.
Clinical trials have already been done on mice in Sweden, funded by Novartis, a Swedish pharmaceutical company. They were able to partially restore hearing in the mice by inducing hair cell regrowth in the inner ear. They hope to expand the trials to humans to improve hearing abilities and reverse progressive hearing damage.
The gene responsible for inner hear hair cell growth is called Atoh1. Once inner ear hair cells finish growing in utero, this gene is normally turned off in humans, which is why it is impossible to regrow the hair cells once they are lost. Scientists hope that they might be able to manipulate genes to turn Atoh1 back on and allow these cells to grow again. The method they use is to implant the gene into a cold virus, which is then implanted into the ear drum with a syringe and a laser.
Participants in preliminary trials have seen slight improvement in hearing, but complete reversal of hearing loss is still out of reach. The hope is that if partial restoration can be achieved, hearing devices can them be used to further restore hearing to the hearing impaired.
There is also work being done to identify alternative genes that play a part in the growth of inner ear hair cells. The hope is that some day advanced techniques will be developed that may lead to complete hearing restoration.
Since hearing loss is caused by more than loud sounds or drug toxicity, there is also research into hearing treatments for genetic hearing loss. In these cases, the culprit may be malfunctioning cells responsible for the sensory part of the ear drum. Scientists hope to find a way to repair those cells and restore hearing.
This new technology is hopeful and soon we may have ways to reverse hearing loss and damage. In the meantime, prevention is essential. Hearing loss can be arrested and sometimes treated if caught early, so don’t wait. Come in today for a hearing test and take control of your hearing and your health!