CAPD terminology (Audi says I'm "hearing impaired.")

[jillio]

Huh. I distinctly recall the audi saying the problem was in the brainstem. She showed me this map of the auditory system in the brain, with lines representing nerves drawn from the ears down to the brainstem, then up into the rest of the brain. Then she pointed at the brainstem, told me about the filter, and told me that based on her tests and my reported experiences, this is where the problem is. My report even explicitly mentioned the brain stem several times.

Is she wrong? Am I misunderstanding her? Am I misunderstanding your explanation?

The 8th cranial nerve (the auditory nerve) is connected to the brainstem, but that is not what is responsible for the difficulties in CAPD. The problems occur in the auditory cortex of the brain. The 8th cranial nerve is one of the neuronal pathways leading to the auditory cortex.

 

[jillio]

Yeah. I can understand speech just fine in a quiet environment. In fact, I think the tests showed that I have above average hearing when not around noise.

Right. Something is amiss between perceiving the sound stimulus and your brain processing it. They aren't quite synched up correctly.

 

[joycem137]

The 8th cranial nerve (the auditory nerve) is connected to the brainstem, but that is not what is responsible for the difficulties in CAPD. The problems occur in the auditory cortex of the brain. The 8th cranial nerve is one of the neuronal pathways leading to the auditory cortex.

So when she was talking about the brain stem, what she was talking about was damage to or problems with the 8th cranial nerve? And somehow that damage interferes with my ability to filter important sounds from unimportant sounds?

 

[jillio]

So when she was talking about the brain stem, what she was talking about was damage to or problems with the 8th cranial nerve? And somehow that damage interferes with my ability to filter important sounds from unimportant sounds?

Not actually. Damage to the 8th cranial nerve results in sensorineural hearing loss. I would imagine she was just showing you the pathways from the ear to the brain. The ear and it's structures receive the sound stimuli in the form of sound waves. The 8th cranial nerve is involved in converting that input into electrical impulses that the brain can interpret.

Most professionals attribute CAPD to some form of head trauma either before, during, or after birth. So that would lead to the supposition that the damage is actually in the auditory cortex, not the neuronal pathways. And by "damage" I mean something such as the auditory cortex being less mature that would be expected, or some sort of a small lesion. Anything that would interrupt the transmission of the electric impulses as it reaches the auditory cortex.

 

[KristinaB]

Just like my daughter has a hard time with people. She has CAPD but has a very mild hearing loss. Her's is more speech recognition problems. Most people we talk to have never heard of CAPD. When we brought it to the doctor's attention, he understood. She never used to say she was hard of hearing, but I think her hearing loss is getting worse and now she says she is hard of hearing. (She's 17)

 

[Anij]

I'm Hoh/Deaf with APD (which is more generalized than CAPD. Technically all CAPD is APD, but not all APD is CAPD even many people, including professionally use the terms interchangeably - largely because pin-pointing the exact APD/CAPD in adults is next to impossible)

I would suggest in both hearing and Deaf environments "Hoh" is both functionally accurate and culturally accurate.
CAPD/APD very literally makes it hard to hard because of the way that the brain mis-interprets sound.

You are NOT a "hearing person, with CAPD" (unless that is the identity YOU want for yourself)

Hoh is perfectly acceptable - and then if someone asks for details (and you feel like sharing) you can explain that you have CAPD which makes you "functionally Hoh"


Hope that helps!!

 

[Jazzberry]

Yes, the cilia, the neuronal pathways, and the areas in the brain specific to processing at different levels or different types of auditory stimuli all work together to determine that which is background and what is important. The cilia are actually the mechanism responsible for sending the stimulus to the 8th cranial nerve, which then uses the neuronal pathways leading to the auditory cortex rather than the brain sending signals to the cilia.

Not actually. Damage to the 8th cranial nerve results in sensorineural hearing loss. I would imagine she was just showing you the pathways from the ear to the brain. The ear and it's structures receive the sound stimuli in the form of sound waves. The 8th cranial nerve is involved in converting that input into electrical impulses that the brain can interpret.

<snip>

I did leave out the 8th cranial nerve (aka the vestibulocochlear nerve) because my understanding was that its function is to only transfer sound and balance information from the ear to the brain, and to also transfer instructions to the cochlea from the brain. So I did lump it into "nerve pathways." Perhaps I should have used the term auditory pathways instead. As far as I can tell that seems to be the more common term for the anatomy structures that starts at the organ of the Corti in the cochlea and ends in the auditory cortex.

Almost every web site that I have read that explains how the cochlea works in detail vs. merely a quick overview indicates that the auditory pathways DO work in two directions: from the inner ear to the auditory cortex and from the auditory cortex to the inner ear.

Some cites:

Auditory System A slide show on the hearing system. On slide 31 of 57:

The actions of the OHCs (my edit: outer hair cells) can be modified by efferent nerve fibers (my edit: nerve fibers that relay messages from the brain or spinal cord to the muscles and organs vs. afferent nerve fibers that relay messages from the receptors to the brain or spinal cord) from the brain.
-- the brain can modify the sensitivity of the cochlea.

From the Yale Ear Lab Yale Ear Lab, Yale University

The exquisite sensitivity and frequency resolving power of the mammalian inner ear depends upon interactions between the two receptor cells of the organ of Corti, inner (IHC) and outer (OHC) hair cells. Whereas inner hair cells appear to function solely as receptors of acoustic information, OHCs function both as receptors and effectors, producing motile responses as a function of transmembrane potential fluctuations. These motile responses are believed to modify the mechanical input to the inner hair cells which receive the majority of afferent innervation, thereby enhancing the gross frequency tuning afforded by basilar membrane mechanics. Currently, we are studying the effector role of the OHC with electrophysiological and displacement measurement techniques using isolated OHCs from the guinea pig. In particular, we use the whole cell voltage clamp to study the voltage dependence of the mechanical response, and the corresponding nonlinear charge associated with the motility voltage sensor. Estimates of the mechanical frequency response are made in order to assess the potential significance of OHC motility in the in vivo feedback scheme. In addition to the work on OHCs, we are also involved with studies on electrical coupling in the supporting cells, as well as characterization of the ionic currents in these cells and in spiral ganglion cells.

[ed. note, I added the bolding and the underline to the quoted text. ]

My understanding was that the more complicated hearing processes occur in the:

* Ear where first the sound pressure is converted into mechanical vibrations (middle ear) and then the vibrations are transduced into electrical impulses (inner ear or the cochlea).

and the

* Auditory cortex where the information from the cochlea is processed into information we use such as words and music.

FWIW, while doing some googling to check my memory, I see that the auditory nerve includes some "relay stops" or identifiable masses of nerve cells on the way to the auditory cortex. I bolded the "relay stops" in the below quote:

Biological Psychology: Chapter 9 Summary & Outline

Afferents from the inner hair cells transmit auditory information into the cochlear nuclei of the brainstem. Cochlear neurons project bilaterally to the superior olive, which in turn innervates the inferior colliculus. From there auditory information is relayed to the medial geniculate and then primary auditory cortex in the temporal lobe.

The above web site only gives an outline and summary of the textbook. So I googled each of the above "relay stops" names. Unfortunately , it was really too much for me to cover as I had other things to take care of this evening and most of what was available wasn't a light read. However, it appears that each "relay stop" may have a function in the hearing process other than simply relaying information from the ear to the brain and from the brain to the ear. When time permits, I hope to look into these structures some more and understand their purposes better.

 

[Jazzberry]

I'm Hoh/Deaf with APD (which is more generalized than CAPD. Technically all CAPD is APD, but not all APD is CAPD even many people, including professionally use the terms interchangeably - largely because pin-pointing the exact APD/CAPD in adults is next to impossible)

I would suggest in both hearing and Deaf environments "Hoh" is both functionall accurate and culturally accurate.
CAPD/APD very literally makes it hard to hard because of the way that the brain mis-interprets sound.

You are NOT a "hearing person, with CAPD" (unless that is the identity YOU want for yourself)

Hoh is perfectly acceptable - and then if someone asks for details (and you feel like sharing) you can explain that you have CAPD which makes you "functionally Hoh"


Hope that helps!!

Anij, I'm glad you posted because I changed my mind. I think it would be too much for most people to get into CAPD. In fact based on my experience with many hearing people, I would not try to explain it to most hearing people. Some of them can get nasty and besides, often it's better to keep it simple.

Sometimes when hearing people know more than a few hard of hearing people they tend to get curious or confused. In that case I'll explain that hearing tends to be much more complicated than vision and that hearing aids don't help hearing as much as a pair of glasses usually helps someone to see better. I also explain that each hearing loss tends to be as unique as a snowflake.

Joyce, if you feel you need to give any explanations to the people that you see more often, you might just want to say that compared to other people who have hearing loss you tend to hear well in quiet, just as well as a hearing person in fact, but that when it gets noisy you don't hear well. And you may need to explain that it doesn't take much noise to get you to the point where you stop hearing well. (If that is true for you, I'm not familiar with CAPD.)

 

[Anij]

urgh - sorry for the Deaf (Dead) typo! (I think that's the first time I've done that lol!)

BTW, I thought I'd add that within my local Hoh/Deaf Community we have a number of people with APDs ... they all refer to themselves as Hoh.

 

[joycem137]

I'm Hoh/Deaf with APD (which is more generalized than CAPD. Technically all CAPD is APD, but not all APD is CAPD even many people, including professionally use the terms interchangeably - largely because pin-pointing the exact APD/CAPD in adults is next to impossible)

I would suggest in both hearing and Dead environments "Hoh" is both functionall accurate and culturally accurate.
CAPD/APD very literally makes it hard to hard because of the way that the brain mis-interprets sound.

You are NOT a "hearing person, with CAPD" (unless that is the identity YOU want for yourself)

Hoh is perfectly acceptable - and then if someone asks for details (and you feel like sharing) you can explain that you have CAPD which makes you "functionally Hoh"


Hope that helps!!

Given how much of an alien and outsider I feel like in many hearing situations because of my inability to hear people, I don't really feel all that tied to a "hearing identity." By the same token, I'm not about to claim a new identity without first fully understanding the implications of such.

I'm a speaker for LGBT rights and social justice issues. I'm very sensitive about the idea of appropriating someone else's labels. I have a strong distaste for the idea of speaking on behalf of other people or claiming an identity that isn't mine.

"functionally HoH" sounds pretty accurate, given my experiences. My friends have been thinking that I was "HoH" for a long time now, and I know I give a lot of people that impression. They just get confused when I seem hearing in some situations, and HoH in others. When I was explaining this to my ASL teacher, I suggested "HoH" signed at the forehead as a potentially useful sign. He laughed but didn't comment further.

Thanks for your thoughts. I appreciate them.

 

[joycem137]

Anij, I'm glad you posted because I changed my mind. I think it would be too much for most people to get into CAPD. In fact based on my experience with many hearing people, I would not try to explain it to most hearing people. Some of them can get nasty and besides, often it's better to keep it simple.

I explained it to a few of my coworkers today, and they seemed to get the whole "My noise filter doesn't work" thing. Of course, these are close coworkers. I don't think I'd discuss this with folks just generally out in the world. Probably not even with coworkers in generally. And really, I just talked about it today because I'm still kinda reeling from the diagnosis.

Joyce, if you feel you need to give any explanations to the people that you see more often, you might just want to say that compared to other people who have hearing loss you tend to hear well in quiet, just as well as a hearing person in fact, but that when it gets noisy you don't hear well. And you may need to explain that it doesn't take much noise to get you to the point where you stop hearing well. (If that is true for you, I'm not familiar with CAPD.)

That's about right. In quiet situations, I hear quite well. The tests I took showed that I eve have somewhat above average hearing in those situations. But even the slightest noise can disrupt that hearing. Someone picking up a sheet of paper, putting on a jacket, rubbing their feet on the floor... Even a passing car or gust of wind... all of that can cause my hearing to start to falter significantly, and thus begins the guessing games of "What do I think that person said, now?" Plus, tests aside, I find that even in quiet environments I have to really focus to hear someone clearly. If my attention wavers even a little bit, or if I have to think hard about something someone said, I can easily lose comprehension.

 

[joycem137]

urgh - sorry for the Deaf (Dead) typo! (I think that's the first time I've done that lol!)

BTW, I thought I'd add that within my local Hoh/Deaf Community we have a number of people with APDs ... they all refer to themselves as Hoh.

Interesting. Does anyone ever feel that they are being inaccurate or appropriating that term?

 

[Anij]

My friends have been thinking that I was "HoH" for a long time now, and I know I give a lot of people that impression. They just get confused when I seem hearing in some situations, and HoH in others.

Thanks for your thoughts. I appreciate them.

Actually, that's a lot of what being Hoh is - hearing fairly well in some situations (quiet, familiar voices etc) and clearly being Hoh in others.

The only reason to add on things like "kinda" or "a little" to Hoh is if doing so makes YOU feel better/more comfortable, because in truth adding on things like that just confuses people (hearing and hoh/d/Deaf).

From a medical standpoint, the way you perceive sounds/understand voices makes you Hoh & it's completely accurate to call yourself Hoh (in ASL using the standard Hoh "HH" sign ... I wouldn't suggest modifying it as it's likely to confuse more than clarify)

 

[Anij]

Interesting. Does anyone ever feel that they are being inaccurate or appropriating that term?

No, because it's an accurate description to say that people with CAPD/APD are hard of hearing (hoh). If you can't function as a "hearing person" in situations where there is background noise, people chatting etc ... that's being Hoh.

In your situation, your specific Hoh "type" is CAPD/APD - versus "conductive", "sensorineural" or "mixed".

 

[dogmom]

with my auditory processing issues, learning disability and peripheral hearing loss I have generally called myself hoh "out there" with hearing and signed H-H with Deaf.

trying to explain the different variables takes too long for most people and they generally don't care. The most I add is something like - I have learning disability and/or may not hear you well. I may need you to show and model <something> to me instead of tell me.

 

[dogmom]

everyone for all your thoughts and input in this section

Joyce, I also liked what you wrote about social justice/appropriation...think you and I are very similar in that way

 

[joycem137]

Not actually. Damage to the 8th cranial nerve results in sensorineural hearing loss. I would imagine she was just showing you the pathways from the ear to the brain. The ear and it's structures receive the sound stimuli in the form of sound waves. The 8th cranial nerve is involved in converting that input into electrical impulses that the brain can interpret.

Most professionals attribute CAPD to some form of head trauma either before, during, or after birth. So that would lead to the supposition that the damage is actually in the auditory cortex, not the neuronal pathways. And by "damage" I mean something such as the auditory cortex being less mature that would be expected, or some sort of a small lesion. Anything that would interrupt the transmission of the electric impulses as it reaches the auditory cortex.

I have to admit, Jillio... All of this is losing me a bit. You seem to know what you're talking about, but I'm having some trouble understanding. When the audiologist sent me away, she gave me a sheet of paper with 4 different "general locations" for CAPD: Brain stem, Posterior, Anterior/Inter-hemispheric, and right hemisphere. She said that I primarily have the first one, with a touch of the third. Do you know what she was talking about there and how that ties in with what you're talking about?

Also, if you have a link to some information I might read, that could be helpful.

 

[joycem137]

everyone for all your thoughts and input in this section

Joyce, I also liked what you wrote about social justice/appropriation...think you and I are very similar in that way

I've been studying cultural oppression stuff for too long to claim membership to a culturally oppressed minority group just like that. I've been raised to think of myself as a member of the majority in this case: A hearing person. Whether or not that's correct, the cultural baggage associated with that doesn't just go away because I discovered that I've had a hearing disability all my life.

That's why I'm here asking about the appropriate terminology before I go around doing something like claiming to be "Hoh" or anything like that. I want to understand what people already in the community think about CAPD and its relationship to the Deaf/HoH community. Is it related? Separate?

I really appreciate all of the perspectives that I'm reading about here. It's very helpful to this process. Understanding the implications of my diagnosis to my identity is actually one of the hardest things I'm dealing with right now. The diagnosis itself is actually a bit of a relief, because now I understand why I've never fit in at hearing parties, never liked crowded restaurants, struggled with certain things in work and school, etc. It's all connected to this: to not being able to hear and understand people when they talk.

 

[jillio]

I have to admit, Jillio... All of this is losing me a bit. You seem to know what you're talking about, but I'm having some trouble understanding. When the audiologist sent me away, she gave me a sheet of paper with 4 different "general locations" for CAPD: Brain stem, Posterior, Anterior/Inter-hemispheric, and right hemisphere. She said that I primarily have the first one, with a touch of the third. Do you know what she was talking about there and how that ties in with what you're talking about?

Also, if you have a link to some information I might read, that could be helpful.

I know. This can get quite complicated and confusing.

The spiral ganglion contains all information sent to the brain. In the brainstem, this information from the spiral ganglion is transferred to the 8th cranial nerve at the cochlear nucleus. If the problem creating the symptoms of CAPD occurs here it is related to the brainstem. However, problems occuring at this point in the auditory pathway more often lead to deafness.

The cells in the cochlear nucleus in the brainstem send axons out that activate the inferior colliculus of the mid-brain. (The cochlear nucleus is a brain structure. It is not the same as the cochlea of the inner ear.) From the inferior colliculus axons are sent out to a specific area of the thalamus, which in turn, sends information to the auditory cortex. Any problems in this relay system could result in some of the symptoms of CAPD.

There are several areas of specialization within auditory cortex. Lesions or injury to any of these areas will cause specific symptoms. The auditory cortex of the right hemisphere has a specialization area that processes the non-verbal aspects of speech, such as prosidy, inflection, etc. Problems in this area would lead to the understanding of the actual words in speech, but not the intent communicated by the words. The surface neurons of the auditory cortex are tonal, in that different ones process different types of sound. They also allow for discrimination of various sounds. A problem here would lead to the symptoms you describe such as not being able to make out words in a crowded environment. Because in a quiet enviornment, you are able to understand and derive meaning from the actual words, it would lead to the supposition that your problem is not in that area. Problems in that area would be more like the "pure word deafness" that I described earlier.

It really has never been determined exactly what causes the interruptions in processing that lead to CAPD, but from the symptoms expressed, it can be narrowed down to a breakdown in a specific area responsible for specialized processing. Once the information reaches the auditory cortex, there are many areas of specialization that it is transferred to. A breakdown in the transfer to any of these areas will create some of the symptoms seen in CAPD. Just like with tinnitus, CAPD is a problem at the neurological point in "hearing", not the actual auditory structures of the ear.

I don't have a link immediately available, because I am relying on several years of knowlege gained in studying neurological psychology. However, let me search the data bases, and if I can't find anything you can link to directly, I will save the article and get it to you. Just give me a bit of time to check all the databases.

In the meantime, if you have questions, just keep asking.

 

[jillio]

I did leave out the 8th cranial nerve (aka the vestibulocochlear nerve) because my understanding was that its function is to only transfer sound and balance information from the ear to the brain, and to also transfer instructions to the cochlea from the brain. So I did lump it into "nerve pathways." Perhaps I should have used the term auditory pathways instead. As far as I can tell that seems to be the more common term for the anatomy structures that starts at the organ of the Corti in the cochlea and ends in the auditory cortex.

Almost every web site that I have read that explains how the cochlea works in detail vs. merely a quick overview indicates that the auditory pathways DO work in two directions: from the inner ear to the auditory cortex and from the auditory cortex to the inner ear.

Some cites:

Auditory System A slide show on the hearing system. On slide 31 of 57:



From the Yale Ear Lab Yale Ear Lab, Yale University

[ed. note, I added the bolding and the underline to the quoted text. ]

My understanding was that the more complicated hearing processes occur in the:

* Ear where first the sound pressure is converted into mechanical vibrations (middle ear) and then the vibrations are transduced into electrical impulses (inner ear or the cochlea).

and the

* Auditory cortex where the information from the cochlea is processed into information we use such as words and music.

FWIW, while doing some googling to check my memory, I see that the auditory nerve includes some "relay stops" or identifiable masses of nerve cells on the way to the auditory cortex. I bolded the "relay stops" in the below quote:

Biological Psychology: Chapter 9 Summary & Outline



The above web site only gives an outline and summary of the textbook. So I googled each of the above "relay stops" names. Unfortunately , it was really too much for me to cover as I had other things to take care of this evening and most of what was available wasn't a light read. However, it appears that each "relay stop" may have a function in the hearing process other than simply relaying information from the ear to the brain and from the brain to the ear. When time permits, I hope to look into these structures some more and understand their purposes better.

It would appear that you are confusing the "cochlea" with the "ccochlear nucleus." They are not one and the same and they do not perform the same functions.

There is nothing in what you posted that suggests that information is sent from brain to cochlea. When you are referring to cillia, they are located only in the cochlea of the inner ear. The pathways from the cochlea to the brain are ascending, not descending.