By the age of 65, experts estimate that nearly one in three adults experiences some degree of age-related hearing loss. To be sure, a number of different factors contribute to age-related hearing loss, but for years scientists have believed that the weakening or death of sensory hair cells within the inner ear was the primary cause. Recently though, a team of researchers may have identified a different cause for this type of hearing loss.
Hearing Loss in Mice
In order to identify the root cause for age-related hearing loss in people, the team of scientists examined the auditory systems of older mice. What they discovered was that mice of advanced age actually had a higher number of connections between the nerve cells and the sensory cells in their inner ear.
On the surface, this increased number of connections might seem like a good thing. Logically, the more connections between sensory cells and nerve cells, the better a person’s hearing, right? Unfortunately, that’s not quite the way it works.
In fact, nerve cell connections are known to inhibit hearing, and the research performed with the mice confirmed this fact. For the study, researchers used electrical signals to determine the hearing ability of the mice, and they found that the greater number of nerve cell connections, the more impaired the subject’s hearing.
Turning the Volume Down
In order to understand how increased nerve cells can impair hearing, think of the connections between the inner ear and the brain as a one-way street. These nerve cells can either take auditory signals from the ear to the brain or, conversely, they can take information from the brain to the inner ear.
When the auditory systems pick up a sound that is excessively loud, the nerve cells receive a signal from the brain to effectively dampen the amplification provided by the hair cells in the inner ear. So the more active a person’s nerve cells, the more the volume on incoming sounds is turned down.
If the research team’s findings are correct, and nerve cells grow more connections and become more active during advanced age, then this could be a major cause of age-related hearing loss.
Obviously more testing will need to be done in order to determine how much nerve cell activity can impair hearing loss. But the more that scientists and doctors understand about the causes of age-related hearing loss, the more they can do to prevent it.
If you or someone you know would like to learn more about hearing loss and how to treat it, please feel free to schedule a consultation or contact one of our representatives today!