Hearing loss and deafness happens when the brain doesn’t get sound signals because something is wrong with the hearing system. There are two main types of hearing loss, depending on where the problem is:
Sensorineural hearing loss is caused by damage to the hair cells or auditory nerve in the inner ear. This makes it harder to pick up background sounds, which lowers the quality of the sounds you hear.
Conductive hearing loss happens when something, like ear wax, makes it hard for sounds to get into the ear. Sounds are softer and sometimes have a muffled quality.
In summary, conductive hearing loss is often temporary and treatable, but sensorineural hearing loss is almost always permanent. Sensorineural hearing loss is the most common hearing loss that we see.
Scientists worldwide have been looking into how sensorineural hearing loss can be fixed because they know there needs to be a solution. Here are a few of these projects.
The Stanford Initiative for Healing Hearing Loss
The Stanford Initiative for Healing Hearing Loss (SICHL) is a group of academics who work together to find ways to fix the inner ear, bring back lost hearing balance, and lessen tinnitus. Over 100 professors, scientists, and technicians are working on this goal and putting a cure into clinical trials.
Researchers have already found that genetics play a significant role in most of these causes of hearing loss, whether from noise, toxins, or aging. Hearing loss is thought to be caused by a few hundred genes, but only about half of them have been found. By discovering these genes, the work at SICHL is meant to fill in this knowledge gap.
Even though the project is just getting started, more money will speed things up and give hope to millions worldwide who have permanent sensorineural hearing loss.
DFNB9
An international consortium of scientists has found a way to help mice with hearing loss.
Hearing loss caused by noise or gets worse with age happens to adults after the cochlear, the organ that helps us hear, is fully developed. This kind of hearing loss was thought to last forever. But a study done by scientists from the US and France found that gene therapy can be used to fix hearing problems even after the cochlea is fully formed.
They also used a new gene therapy method to help mice with a form of deafness similar to that found in humans get their hearing back (called DFNB9).
In their work with mice, the researchers have shown that this method can be used for genes too big to fit into one virus particle. This means that this method could treat more types of hearing loss.
Since researchers have shown that it works for one type of hearing loss, they can use this method to test other genes to see if it can fix problems in other types of hearing loss. In the long run, this could be a step toward using this technique to make gene therapy that can be tested on people with hearing loss.
Gene Therapy
The Department of Otolaryngology at Columbia University is one of three places worldwide running a clinical trial to treat hearing loss with cellular regeneration.
The study is about a drug that contains genes and has been shown to make hair cells in lab tests. Academics are doing this research in the hopes that one day damaged inner ear cells will be able to grow back and fix the problems that cause hearing loss. At the moment, cochlear implantation is the only way to treat severe hearing loss caused by the death of hair cells.
“We hope that the procedure will allow doctors to regrow the important hair cells that help people hear,” said Dr. Lawrence Lustig, Chair of the Otolaryngology Department—Head and Neck Surgery. “This could mean that people won’t need hearing aids or cochlear implants.”
Hearing aids are the best treatment right now.
Even though this is exciting news, it may be long before hearing loss treatments are sold in stores. As of now, there is no way to bring back hair cells that have died in the inner ear.
But hearing aids can help you hear and understand sounds much better by making them louder and clearer. Hearing aids have a microphone, an amplifier to make sounds clearer, and a receiver that sends the signal into the ear canal.
Because of improvements in hearing aid technology, hearing aids now make fuller sounds and can handle noise better than ever. Hearing aids are not yet as good as your ears, but many people have found that they make their lives much better.