Deafness – Part 2

Continued from the previous blog.

Noise-induced hearing loss. Hearing damage from noise exposure typically occurs in a very restricted frequency range, creating a gap in the sequence of frequencies that can be heard. The gap is usually in the high-frequency range, which can affect a person’s ability to understand speech. However, noise damage can sometimes affect such a narrow frequency range that the person may not even be aware that he has hearing loss.

Protecting your ears from loud sounds can reduce the potential for hearing loss caused by noise exposure. Many comfortable forms of hearing protection are available, including earplugs, which fit into the ear canal, and earmuffs, which secure over the ears with a band. Some people are reluctant to wear hearing protection in noisy environments because they are concerned they won’t be able to hear others talking to them. This is not something to be concerned about, however, because most people talk louder in noisy situations, so it is possible to hear conversations even with ear protection.

I have some noise hearing loss from the military, but the tests were so poorly done, that I was not able to contest the results. Over the years, I have become more acutely aware of some sounds and often have to leave some gatherings when music is too loud.

Age-related hearing loss. As we age, hearing loss occurs gradually, beginning with the high frequencies. In general, vowels, which account for the loudness of speech, are in the low-frequency range, while consonants, which provide the clarity of speech, are in the high-frequency range. Therefore, high-frequency hearing loss may not affect how loudly sounds are heard, but it can make speech less clear and, as a result, more difficult to understand. This is especially the case when watching television or listening to the radio, where speech is often fast and where visual cues, such as lip movements and body language, are not as readily available, as well as in noisy situations.

As far as age-related changes in hearing are concerned, it’s important to remember that the ear alone is not responsible for hearing. Sound is converted into electrical signals that travel from the cochlea through a series of nerve pathways to the brain for interpretation. In addition to problems associated with physical deterioration of the hair cells in the cochlea, there are age-related changes in the processing ability of the hearing-related nerves (the central processing disorders mentioned earlier) as well as cognitive changes that may slow a person’s ability to understand speech. These changes can have a profound effect on a person’s verbal communication abilities, regardless of whether hearing loss is present. For example, a common complaint of some older people is that people talk too fast. This is because as we age, the mental processes that are needed to understand speech can overload when information is presented too rapidly. In a study, conducted at the Veterans Affairs National Center for Rehabilitative Auditory Research (NCRAR) in Portland, Oregon, it was found that older people who have poorer performance on certain cognitive tests (those related to thinking, learning, and remembering) also perform poorly on speech recognition tests (tests that use lists of sentences speeded up by a computer).

Age-related hearing loss may not be immediately evident to the person whose hearing is damaged, and as a result, his hearing may be significantly diminished before he seeks help. Indeed, older people may not think they have hearing loss at all. They can still hear a lot of sounds loudly, so they simply think that other people are mumbling. In fact, this type of hearing loss is often noticed first by friends and family who find communication becoming increasingly difficult.

Age-related hearing loss progresses at different rates in different people. Some people still have very little loss even in their 80s, although that isn’t common. It is not clear what makes some people more susceptible to hearing loss than others, but as with any other age-related condition, good nutrition, physical activity, and good prevention practices (hearing protection, in this case) can contribute to lessening the effects or delaying the onset of hearing loss.

Infection or earwax can block ear canals and reduce hearing. Earwax can be safely removed in most cases, but earwax that has hardened requires some treatment to be safely removed.

The link between diabetes and hearing loss has been debated since the 1960s or before, and the results show that a relationship exists even when researchers account for the major factors known to affect hearing, such as age, race, ethnicity, income level, noise exposure, and the use of certain medications.

Diabetes may lead to hearing loss by damaging the nerves and blood vessels of the inner ear, the researchers suggest. Autopsy studies of diabetes patients have shown evidence of such damage.

Diabetes is a group of diseases marked by high levels of blood glucose resulting from defects in insulin production, insulin action, or both. Afflicting nearly 21 million people in the United States, it is a major cause of heart disease and stroke and the most common cause of blindness, kidney failure, and lower limb amputations in adults. Prediabetes, which causes no symptoms, affects about 54 million adults in the United States, many of whom will develop type 2 diabetes in the next 10 years. Prediabetes raises the risk of a heart attack or stroke even if diabetes does not develop. People with prediabetes can often prevent or delay diabetes if they lose a modest amount of weight by cutting calories and increasing physical activity.

For other information about diabetes and deafness or hearing loss please read this, this, and this article.

Deafness – Part 1

This is a topic that has many opinions and they are almost evenly divided into the opposing sides. There are those that do not believe diabetes causes hearing loss and those that can offer convincing evidence that it does cause hearing loss. They do agree that there are different types of hearing loss and can have different effects on how sounds are heard and understood. The different types of hearing loss tend to have different causes, and it appears that having diabetes can contribute to the development of certain types of hearing loss. Damage can occur anyplace along the hearing pathway. The location of the damage is the determining factor that determines the type of hearing loss.

The different types of hearing loss are:

Conductive hearing loss (outer and middle ear). Trauma to the structures of the ear that physically transmit sound, such as the eardrum and the bones in the middle ear, can result in conductive hearing loss, which reduces the ear’s ability to physically conduct sound vibrations. The eardrum can be damaged by chronic infection, trauma resulting from pressure changes in the ear (such as those that occur in deep-sea diving), or blunt force to the ear or head. The tiny bones in the middle ear also can be damaged by blunt force. A condition called otosclerosis, which involves abnormal growth of bone in the middle ear, can reduce the strength of the sound vibrations that are transmitted into the cochlea, thereby reducing the volume at which sounds are heard.

Conductive hearing loss causes a reduction in the overall volume of sounds, but if speech can be made loud enough, by means of a hearing aid or the speaker talking louder, for instance, it can most often be understood. In many cases, areas of the ear involved in conductive hearing loss may be treated with medicines or repaired with surgery.


Sensorineural hearing loss and central processing disorders (inner ear and central hearing pathway). Damage to the inner ear or to structures along the nerve pathway is called sensorineural hearing loss because it involves either the delicate sensory hair cells in the cochlea or the hearing nerve, and sometimes both. When the nerve pathway from the ear to the brain is damaged, this is usually referred to as a central processing disorder. Unlike people with conductive hearing loss, those with sensorineural hearing loss or processing disorders may have difficulty understanding speech even when it is amplified. In fact, too high a volume can result in distortion of the speech, causing an unpleasant sound and making it even more difficult to understand.

A person whose sensorineural hearing loss is caused by damage to the hair cells in the cochlea typically has difficulty hearing sounds at particular frequencies, or pitches. This is because each group of hair cells is sensitive only to one frequency, and when any damage occurs, some hair cells may be affected more than others. The hair cells nearest the entrance from the middle ear, which detect high-frequency sounds, seem to be more susceptible to damage related to aging and noise. This can lead to hearing loss in the high-frequency range, making it difficult to understand speech, which contains a mix of low- and high-frequency sounds.

Sudden sensorineural hearing loss. Sensorineural hearing loss that appears suddenly can have a number of causes, including a blow to the side of the head or a sudden loud sound like an explosion. This type of hearing loss can involve a wide range of frequencies, depending on the nature of the injury. Sudden sensorineural hearing loss that has no known explanation occurs only rarely, and in a large percentage of these incidents, the people recover their hearing spontaneously. (Many physicians think these cases are the result of viral infections, but this explanation has not been confirmed.)

There have been reports of sudden sensorineural hearing loss associated with diabetes, but this is extremely rare. However, there is evidence that high blood pressure may increase damage to the small blood vessels in the cochlea of people with diabetes, which could result in sudden sensorineural hearing loss. A recent study found that people with diabetes and sudden sensorineural hearing loss were more likely to have higher blood pressure, higher cholesterol, and a higher HbA1c (an indicator of blood glucose control over the previous 2–3 months) than people with diabetes but no sudden hearing loss.

If you experience sudden hearing loss, you should report it to a physician, preferably an otolaryngologist (ear, nose, and throat (ENT) specialist). It is important to get medical attention as soon as possible, because specific medicines can often recover some or most of the hearing if they are administered early.

Concluded in next blog.

Hearing Loss Now Linked to Diabetes

Since I have type 2 diabetes, this is not news to me, but from discussions I have had with a few type 2 people with diabetes, I know many are not aware of the possibility of hearing loss. A key to understanding this is this statement from the study authors, “high blood glucose levels can damage vessels in the stria vascularis and nerves diminishing the ability to hear.” Stria vascularis is the upper portion of the spiral ligament that contains numerous capillary loops and small blood vessels, and is termed the stria vascularis. It produces endolymph for the scala media, one of the three fluid-filled compartments of the cochlea.

Like vision loss, it is the small blood vessels that are damaged by extended high blood glucose levels; therefore, hearing loss develops. Yet even this is controversial as most studies are inconsistent in results, that is, they have faults in research protocols so that the results are always inconsistent. It is still believed that over time, high blood glucose levels can cause damage and diminish the ability to hear. A study by the University of Japan found that people with diabetes have more than two times higher prevalence of hearing impairment than those without diabetes.

One of the strongest critics of the study states that the study is an observational association and additional studies are needed to clarify the relationship between diabetes and hearing loss. When researchers compare diabetics with non-diabetics, these observational studies cannot prove a cause-and-effect relationship, only a correlation between diabetes and hearing problems.

The connection between hearing loss and diabetes was stronger among people who were 60 years of age or younger rather than among older adults. The likelihood of having hearing impairment in this group was 2.6 times higher. Comments agreed and said this is consistent with the idea of poor blood glucose management, which damages blood vessels and nerves throughout the body and not simply old age.

It is important to be proactive in your care. If you notice any hearing loss, report this to your doctor. According the American Diabetes Association almost 26 million people have diabetes. More than 34 million Americans have some type of hearing loss and this number is rising as the baby boom generation ages.

Diabetes Does Cause Hearing Loss

This is another diabetes complication that often is ignored. It is ignored because people do not consider hearing loss as being a complication. Consider how many of our organs may are affected by diabetes. If you have diabetes, you may figure that you are at twice the risk of having hearing loss.

One way to avoid this and most diabetes complication is to manage your diabetes by maintaining careful management of your blood glucose levels. Keeping these as close to normal or at normal is good for keeping complications away. This applies to all complications. Let your blood glucose levels take off for the stratosphere and your odds of developing the complications go up with them.

With hearing, it is the small blood vessels and nerves in your inner ear that become damaged by high blood glucose over a period of time. Autopsy studies of diabetes patients have shown the evidence of this damage.

The study researchers discovered the high rate of hearing loss with diabetes after analyzing the results of a nationally representative sample of U.S. Adults. The hearing tests measured the participants' ability to hear low, middle, and high frequency sounds in both ears. The researchers discovered the link between diabetes and hearing problems and that it was evident across all hearing frequencies, but was more pronounced in the high frequency range.

Comparisons between those without diabetes and those with diabetes were this. At the low to mid-frequency sounds for people without diabetes at nine percent to people with diabetes of 21 percent. The high frequency hearing loss was 32 percent (without diabetes) to 54 percent (with diabetes).

The alarming fact for me was for people with prediabetes. Just because they do not have diabetes, does not exempt them from hearing loss. They exhibited a 30 percent higher rate of hearing loss than those with normal blood glucose.

This is just another reason for preventive action for people with prediabetes and strict blood glucose management for all people with diabetes. If you think you are immune to hearing loss, you are in for a shock if you let your blood glucose management have an extended holiday.