What You Need to Know about Sensorineural Hearing Loss
Sensorineural hearing loss is the most common form of all types of hearing loss. The bad news with this condition is that it involves permanent damage to one of three parts of the hearing system; damage which cannot be corrected. The good news is that hearing aids can be used to recreate what's been lost by the physical damage, allowing patients some semblance of continued hearing. Although that hearing does not sound "natural" to the patient, it is a realistic enough simulation allowing the patient to continue to lead a normal life.
It is estimated by doctors that upwards of 80% of all patients who need hearing aids are suffering from sensorineural hearing loss. Sometimes the problem is the result of damage to the cochlea, a bundle of nerve endings in the inner ear that resemble tiny hairs. Other times the damage is in the auditory nerve or embedded somewhere in the brain itself. Depending on what's causing the issue, treatment options will vary.
How It All Works
In order to hear, your brain requires a series of events to take place within your body. To begin with, external sound waves enter the outer ear and are channeled into the inner ear through a canal which progressively gets narrower. This narrowing amplifies the sound waves so that when they reach the inner ear they stimulate the cochlea with maximum effect. The tens of thousands of nerve endings contained in the cochlea then send auditory signals through the auditory nerve into the brain. The brain interprets those signals as the various sounds we hear.
Any physical damage to the components of the year which result in hearing loss can be diagnosed as sensorineural in nature. But typically, the three most commonly damaged components are the ones we previously spoke of: the cochlea, the auditory nerve, or the brain receptors. Of those three, cochlear damage is the most common.
Cochlear damage is a normal part of aging, especially in individuals who spent a good part of their working careers in very noisy environments. For example, someone who worked 40 years in a noisy manufacturing plant and failed to wear earplugs is extremely likely to develop sensorineural hearing loss as he ages. The constant assault of the loud noises slowly wears down the cochlea and damages the nerve endings. The natural process of breakdown that comes from aging simply makes matters worse.
Other things that can contribute to sensorineural hearing loss include:
- prolonged inflammation of the inner ear
- diseases and illnesses such as measles, meningitis, syphilis, and mumps
- autoimmune conditions which attack the inner ear
- Ménière's disease
- a reaction to medications - known as otoxicity
- direct injuries to the ears or skull
- genetic mutation
In most cases sensorineural hearing loss is dealt with using external hearing aids. Two of the more common types are known as behind-the-ear (BTE) and in-the-ear (ITE). When the issue is being caused by brain sensory problems it is possible to have technologically advanced implants that use microchips and electric voltage to stimulate the brain. In either case it must be noted that these treatments do not restore natural hearing. Rather, they create a simulation which the brain is able to interpret reasonably well.
Symptoms of Sensorineural Hearing Loss
The symptoms of this type of hearing loss depend on where the damage is located and the severity of it. In the majority of cases the first symptom is the inability to hear certain frequencies. That's because the various nerve endings in the cochlea are all responsible for different frequencies and combinations thereof. You may be suffering from damage to only a small portion of those nerve endings, which means only certain frequencies are being interrupted. A standard hearing test is very successful in determining this type of damage.
Another common symptom is when patients have trouble distinguishing specific words or tones in conversation. For example, one individual might have trouble distinguishing between the "S" and "F" sounds. Another individual may fully understand a female with a high-pitched voice but have extreme difficulty with a male who has a low pitched voice. These difficulties in distinguishing sounds and tones in conversation indicate that specific parts of the cochlea have been damaged.
In extreme cases, damage to the cochlea, auditory nerve, or brain receptors can be severe enough to make a person completely deaf. In such cases the only effective treatment is normally the use of surgical implants. As long as some hearing is still possible however, the use of external hearing aids is preferred.
Experimental Treatments
The area of sensorineural hearing loss is continually changing as science learns more and more. Researchers believe that in some cases, the type of damage that causes sensorineural hearing loss can be reversed if it is treated soon enough. For example, some individuals suffering ear damage as the result of an explosion have fully recovered when steroids were injected at the site of the injury within a short period of time after it was sustained.
In other studies, researchers have found a link between vitamins A and E in reducing some amount of physical damage to the ears. Their tests with these vitamins are by no means conclusive at this point, but the research does show promise for those whose sensorineural hearing loss is not extreme. Hopefully, as research continues science will find more effective ways to reverse some of the damage that causes this type of hearing loss.
If you believe you're suffering from sensorineural hearing loss, you should make an appointment with your doctor or an audiologist so it can be confirmed. If so, remember that you are not alone. Millions of Americans deal with hearing loss every day. It doesn't have to be the end of your world if you allow your doctor to help you.