August 7, 2012
You may have a hearing loss without knowing it
Loud noise can cause immediate hearing loss. But it can also do harm to your inner ear that you will only experience after some time. And then your hearing will be hard to restore.
Your inner ear has a life of its own. Its main function is to conduct sound signals from the outer ear to the brain so you can process what you hear. If the sound signals are too loud, they can damage the life of your inner ear, and that may lead to hearing loss.
A sudden hearing loss can be treated, but only if it is addressed immediately. After a time without treatment, the hearing loss will be hard to avoid. A study shows that noise that is too low to cause immediate hearing loss may still do harm to your inner ear and because you don’t experience the hearing loss at once, it could be difficult to discover and to treat.
Disconnections in your ear
When your ear is exposed to loud noise, it can damage the tiny hair cells in your inner ear. The job of the hair cells is to send the sound signals to the spiral ganglion neurons that help the brain process sounds. If the spiral ganglion neurons are not in contact with the hair cells, they will retract and will not function.
A study led by PhDs Qiong Wang and Steven Green from the University of Iowa, USA, found that to maintain the connections between the hair cells and the spiral ganglion neurons, a specific tissue is produced. When the hair cells are damaged by loud noise, the production of tissue will stop, the spiral ganglion neurons will retract, and you will lose your hearing.
The results of the study, published in The Journal of Neuroscience, show that even though the hair cells are still functioning for the moment, they will tire over time and eventually stop producing the tissue that the spiral ganglion neurons need to deliver sound signals for the brain to process.
Therefore, you may in fact walk around with a hearing loss because the hair cells in your inner ear are damaged. You just don’t know it - yet.