Hearing loss is a common and serious problem for many people who are exposed to loud noises on a regular basis, and for those advancing in years. Several studies are showing that there is hope for these individuals; there are new advancements in the field of hearing restoration.

Hearing Loss Statistics

The statistics regarding hearing loss among typical Americans are staggering. Some figures regarding hearing issues include:

  • Almost 50 million Americans suffer from at least partial hearing loss
  • Over 26 million suffer from loss of hearing resulting from noise exposure
  • Loss of hearing from noise begins with the ability to hear higher frequencies
  • Age-related hearing loss affects roughly 30 percent of adults between ages 65 and 74, and almost 50 percent of those over 75
  • Almost 60 percent of Iraq and Afghanistan veterans have hearing loss or tinnitus
  • Men are more likely than women to experience hearing loss
  • 2-3 out of every 1,000 children born in the United States have some level of hearing loss

Neutrophin-3 Protein

A recent study out of the University of Michigan has highlighted a protein called Neurotrophin-3 that seems to play an important role in hearing. This protein is involved in transmitting signals for the ears to the brain. It is vital to establishing the ribbon synapse, or the connection between the hairs in the ear and the nerve cells.

When exposed to loud noises, or even just from normal aging, the NT3 protein can become damaged or reduced, leading to hearing loss.

Restored Hearing in Mice

In the new study, researchers were able to increase production of NT3 in mice and restore lost hearing as a result. The study was able to identify those cells that produce NT3, and used gene therapy along with a drug called tamoxifen to increase the amount of NT3 produced.


Those mice which saw increased production of NT3 regained hearing over a 2 week period when compared to a control group. The results indicate that this protein is a core part of the ribbon synapse and has the potential to restore hearing loss from age and noise.

Applying the Results

Scientists are currently researching whether NT3 plays the same role in human ears as it does in mice. This allows them to examine the development and identification of drugs which may create a similar effect in human hearing restoration.

Researchers believe that drug therapy in humans would be far simpler than that used in mice, and would involve repeated treatments until hearing loss was restored. The study authors are not certain whether complete hearing loss could be restored, as the mice tested had only partial loss of hearing.

Promising Findings

Still, the findings are very promising. They indicate that damaged ribbon synapses are a core problem in hearing loss. The findings are the result of fifteen years of research that begin with basic information about the inner ear, and have resulted in restored hearing.

The results of these findings could even be applied across the board to neurodegenerative diseases. This could be an exciting development, indeed.