Can Hearing Loss Be Reversed?

The answer may be yes

- Vanessa Milne

"HI, VANESSA! Nice to see you!" It feels good to hear those words when I see people I know. But I take it for granted that I have even heard that greeting-and, in fact, all other sounds. I never think about how I'm hearing things, how my brain is translating sounds into meaning.

Yet the process is fascinating. The journey of a sound from outside the ear and into the brain, which takes only milliseconds, is mind-bendingly elaborate. First, the sound waves enter each ear and vibrate the paper-thin eardrum. That vibration moves two small bones that sit behind it, which begin to dance in sync with the sound waves' vibrations.

Then a third bone sitting against the cochlea starts to vibrate, and things get really interesting. The cochlea is a peasized, bony structure shaped like a snail shell and filled with fluid. It's lined with tens of thousands of hair cells topped with bundles of miniature tubes called stereocilia. That vibrating third bone beats against the cochlea, like knocking on a door. The cochlea's fluid sways, and the hair cells wave like sea anemones. That movement causes the hair cells to release chemical neurotransmitters, triggering a series of electrical messages that are carried through the auditory nerves into the auditory cortex of the brain, which translates the electrical code into meaning.

The delicate stereocilia and hair cells have a limited lifespan. We start to lose our hearing because, as they're used again and again through a lifetime of exposure to sounds at regular volume or a shorter-term exposure to loud sounds they can become damaged and stop doing their job. Called presbycusis, this age-related, or sensorineural, hearing loss is the most common.

If I had mild to moderate presbycusis, certain consonants would be more difficult to discern, so "Hi, Vanessa. Nice to see you!" would sound like "...i Vane...a. Nice..o ..ee you!"