by Jessica Wilson

While you’re reading this, chances are there’s more than one kind of sound that you might be hearing right now. Whether it be the music that you’re playing in the background, the faint hum of your fan or air conditioning unit, your dog – or that of your next-door neighbor – barking for whatever reason, or vehicles passing by outside your house, you have your healthy set of ears to thank for being able to hear them.

Unfortunately, not everyone gets to fully hear the same sounds as you do (assuming you have normal hearing), especially those who suffer from some form of hearing loss as caused by several common reasons, some of which you may not be aware of.

 

What Are the Three Main Types of Hearing Loss?

 

What may come as a surprise to you, there are three main types of hearing loss that can occur to anyone which are as follows:

  • Sensorineural hearing loss in which the hair cells and auditory nerve in one’s inner ear become damaged.
  • Conductive hearing loss in which the ability to conduct sound waves from outer to inner ear becomes either reduced or completely lost.
  • Mixed hearing loss, or sensorineural and conductive hearing loss occurring at the same time.

 

What Are Some of the Common Reasons for Hearing Loss That You May Not Be Aware of?

 

Conventional medical wisdom has it that two of the most common reasons for hearing loss are old age and prolonged exposure to noise. But hearing loss may be caused, or associated with, the following conditions:

 

1. Diabetes

While diabetes itself plays host to several complications, some of which are life-threatening, one that manifests itself more commonly is hearing loss.

  • Ears have small blood vessels that can get damaged by diabetes more easily as they don’t have any backup blood supply to rely on.
  • Someone diagnosed with diabetes should start controlling their blood sugar as soon as possible by choosing appropriate food to help keep theri hearing intact for a longer period of time despite their condition.

 

2. Stroke

Some of the most common outcomes after someone has suffered a stroke include partial or even full body paralysis as well as speech and memory problems, but it can also cause hearing loss that may either be mild or lead to total deafness.

  • Everyone has a pair of temporal lobes located in the area of the brain below the temples which are responsible for recognizing and processing the various sounds that travel from the ears to the brain.
  • A stroke affecting only one temporal lobe usually ends up in hearing loss that may be mild while total deafness, even if rare in occurrence, can happen as well if a stroke has affected both temporal lobes.

 

3. Playing contact sports

A lot of sports are physical in nature, contact sports even more so as players may sustain injuries on their heads which can result in hearing loss that may go unnoticed if not treated right away.

  • The delicate nature of the ear itself makes it vulnerable to traumatic injuries, especially after the head of someone who’s into contact sports either received a blow or collided with a hard surface.
  • Thus, some contact sports require their players to wear protective headgear that can absorb the impact of blunt force trauma on their heads.

 

4. Foreign object inserted into a child’s ear

If you have a child of your own, they may have innocently tried putting small objects inside their ear that can lead to hearing loss if not removed.

  • If you can still clearly see the small object lodged inside your child’s ear, you can gently pull it out with a pair of tweezers.
  • Otherwise, take your child to a medical professional who can safely remove the foreign object.

 

While many cases of hearing loss are often the result of either aging or overexposure to noise, other causes as to why it occurs for some people aren’t as apparent. Knowing other, less common reasons for hearing loss can help you understand better how it affects other people who, perhaps, haven’t yet reached old age  or don’t even expose themselves to any kind of noise at all.

 

 

Jessica Wilson is a professional health expert who works for some major health industry giants. She currently writes for Membersown and is dedicated to helping people learn more about health related topics along the journey. When she’s not a health advocate, she enjoys some down time traveling or talking with family.

Preliminary research from Smith-Kettlewell Eye Research Institute in San Francisco suggests certain vision problems in older adults is associated with a 50% higher risk of hearing loss.  Here is a summary of the research by Marilyn Schneck and colleagues:

 

446 adults with a mean age of 79.9 years had their hearing screened and underwent an extensive series of visual tests.  The visual tests categorized the subjects according to their acuity in high and low contrast situations where lighting was varied.  Results showed that vision ability in low contrast situations decreased with age (white bars, Figure 1).

Hearing loss was only measured by a hearing screening, not in-depth testing of the type done on the vision of the subjects.  Nevertheless, the results were consistent with what we know about the general population:  hearing loss increases with age (black bars in Figure 1), as did  increased vision impairment, the white bars in Figure 1.

 

Figure 1. Rates of hearing impairment (black bars), vision impairment (white bars) and dual sensory impairment (gray bars) across age groups

 

Of most interest is that subjects who had decreased visual performance were more likely to also have hearing difficulty and that effect was also age dependent (gray bars, Figure 1).

Let’s get back to that “low contrast” part of the study.  If you are like us, low contrast sensitivity doesn’t mean much, so we looked into it further and found this helpful illustration:

 

How it looks to someone with low contrast sensitivity

how it looks to someone with normal contrast sensitivity

 

 

People who have low visual contrast sensitivity see a scene with … not much contrast. It gets all hazy and it is literally hard to see the trees for the forest or whatever background surrounds the trees. Those with normal vision see everything distinctly and  in technicolor, as in the right picture.

When you think about it for a minute, this is an excellent analogy to what happens to people who lose some of their hearing with age. Those people don’t complain that they are deaf — they can still hear.  Instead, they complain that they can’t distinguish speech in noise — that it is all blending together, the clarity is gone, it’s getting hazy.  Though they don’t use the word “contrast,” that is what they are really saying — there is too little contrast between the noise and speech to allow them to easily “hear” in the haze.

This is exciting research although it just scratches the surface.  We are hopeful that the scientists at Smith Kettlewell will pursue this interesting line of research. We’re also hopeful that they will be joined by audiologists and psychoacousticians who will add important hearing measures to the research protocol.  Just as subjects in this study were tested for high and low contrast visual stimulus sets, it would be very useful to know how those same subjects performed on speech-in-noise tests.  If the performance deficits are similar between vision and hearing modalities, the next steps in the research might find similar physiological substrates to explain the findings.

None of this will happen overnight, of course, but we’ll keep checking in and let you know if anything comes up.

 

Reference:

Schneck, M.E., Lott, L.A., Haegerstrom-Portnoy, G., Braby, J.A., Association between hearing and vision impairments in older adults, Ophthalmic and Physiological Optics, Volume 32, Issue 1, pages 45–52, January 2012

 

*This article was originally published at the Audiology condition on July 12, 2016. Images courtesy of nyc.gov and Contrast Sensitivity Testing