Do you feel that you have difficulty hearing and following conversations, even if you’ve passed a hearing test? It’s possible you have hidden hearing loss – a condition that is not well-known or well-researched. Hidden hearing loss is difficult to diagnose because it cannot be detected by traditional hearing tests.
No one is exactly sure how many people have hidden hearing loss. However, one study of more than 100,000 patient records over a 16-year period found that around 10 percent of patients who visited Massachusetts Eye and Ear had a normal audiogram despite complaints about their hearing.
Signs of Hidden Hearing Loss
Unfortunately, there is no established set of guidelines to help diagnose hidden hearing loss. Some potential signs associated with the condition include:
- A strong sense you have hearing loss despite passing a hearing test
- Ability to converse better in quiet settings
- Feeling distracted or having trouble focusing in noisy environments
- Consistently mishearing people
What Causes Hidden Hearing Loss?
When hearing is normal, soundwaves travel through the ear and stimulate tiny hair cells in the inner ear called the cilia. The sound signals are then transmitted from the cilia to the auditory nerve, cross over synapses (which are vital junctions between nerve cells) and are sent to the brain to be interpreted as sound.
In many cases, hearing loss is caused by damage to the hair cells or auditory nerve. This is the type of hearing loss that traditional hearing tests can identify. However, with hidden hearing loss, the issue is with the synapses, which causes the signal to arrive at the brain incomplete.
Research has found that damage to the synapses can be caused by noise exposure. A 2009 watershed study in mice documented that mice exposed to two hours of 100-decibel noise exposure lost half their synapses, despite the cilia surviving.
Audiologists theorize that humans with lost or damaged synapses can still here the beeps in a hearing test at a low volume that people with cell or nerve damage cannot.
How Is Hidden Hearing Loss Treated?
There is not yet a direct treatment for hidden hearing loss, but research is underway to find medications that can prompt neurons to grow new synapses.
In cases where hidden hearing loss is slight or mild, people may benefit from hearing aids that have special speech-in-noise programming, which use directional microphones to amplify sounds in front of them and reduce sounds beside and behind them.
For more information about hidden hearing loss or to schedule an appointment with an audiologist, call the Hearing & Balance Center at Charleston ENT today.