Now that my cognitive abilities have been fully restored (that sounds about right), let’s return to our discussion on how hearing works, in particular auditory disorders. Remember that audio information enters the outer ear, passes through the middle ear, on to the inner ear then goes along for central processing.
When individuals experience hearing problems, it can be caused by a myriad of circumstances. Let’s review some of them and review potential causes. For starters, there are two types of hearing loss: conductive and sensorineural.
Conductive hearing loss is due to damage to the external ear canal, eardrum, and middle ear. Can result from blockage in external ear canal or disorder in middle ear’s ability to transmit mechanical energy to staple footplate.
Causes: Any condition or disease that impedes conveyance of sound in it’s mechanical form through the middle ear cavity to the inner ear. Ear infections can cause conductive hearing loss however, it is usually mild, temporary, and treatable with medicine or surgery.
Sensorineural hearing loss is when sound reaches inner ear but cannot be translated into nerve impulses (sensory loss) or nerve impulses are not carried to the brain (neural loss). Sensory and Neural hearing loss results from inner ear or auditory nerve dysfunction.
Causes: The sensory aspect may be from damage to organ of corti, the inability of the hair cells to stimulate the nerves of hearing, or a metabolic problem in fluids of the inner ear. The neural or retrocochlear (behind the cochlea) aspect may result from damage to the organ of corti that causes the hearing nerves to degenerate, it can also be from the inability of hearing nerves themselves to convey neurochemical information into central auditory pathways.
These impairments do not respond well to treatment and their damage is most often irreversible and permanent. Similar to conductive hearing loss, it can result in a reduced intensity of sound but sensorineural loss results in a distortion of what is being heard.
.:Mixed Hearing Loss:.
Mixed hearing loss is a combination of both conductive and sensorineural.
Causes: May be the result of severe head injury, chronic infection, or one of many rare genetic disorders.
.:Audio Processing Disorder:.
Auditory Processing Disorder (ADP) otherwise known as, Central Auditory Processing disorder (CAPD), is not considered a type of hearing loss but is an umbrella of disorders that affect how the brain processes auditory information. It is the reduced or impaired ability to discriminate, recognize, or comprehend complex sounds, such as those used in words, even though person’s hearing is normal. Individuals with ADP usually hear well in quiet environments but experience issues hearing when noise is present. Electrical signals that come from sound waves into the ear and are sent to the brain arrive with delay or distortion which makes learning or memorizing difficult.
From what we see here, issues with processing affects comprehension and memory but it also makes it difficult to pay attention. This usually begins in childhood and can make it difficult for kids to learn and focus. So if you suspect your child is experiencing hearing issues, get it checked out at the earliest convenience.
Causes: Can be congenital (meaning you are born with it), links to recurrent middle ear infections, head injury, or trauma.
I created an infographic that fully breaks down the various disorders that affect hearing below:
As of now, my hearing is still in tact. Which is a glorious accomplishment if I think back to the decibel levels I’d play my music at when I was younger. I’m also fortunate that in my family there is no history of hearing loss or auditory disorders, just the heavy stuff, like cardiovascular problems. If we refer to the reason I began exploring our hearing sense in the first place, it was due to a pal named Randy Marsh. Now if we take into account that Randy can hear but is only affected in noisy conditions, I’d say that falls under auditory processing disorder. Essentially meaning that as you stated yourself Randy, you do have a brain problem. I’m sure it comes in handy, especially within work settings: “What TPS report? I’m sorry I didn’t catch that try me next week.”