Hearing Loss Linked to Three-Fold Risk of Falling – 02/27/2012

Insight through peers

A little while ago I received a comment on this blog. Richard Rutherford had something very important to share. I feel compelled to provide his thoughts to you all, in it’s own post. The initial reason for that is because of what he put his finger on: the issue of audism related to self destruction-mechanisms. I feel he definitely has a very good point. In addition, we had an exchange of thoughts afterwards, which produced additional noteworthy points (these are expressed at the bottom of this post, after the “letter”!).

expectation-24I had not thought about this issue from the aspect that Richard offered, which is such a beautiful thing about this form of communication (i.e. blogging); one thought or experience leads to another thought. Richard puts it so well in his letter, that I put it here, word for word. (Richard, you should seriously think about writing your own blog :-)  )

As a comment, I would like to say that this issue, even though I didn’t realize it until I read his comment/letter, was one of the major things I worked with during the two years of psychological therapy I underwent in 2006-2008.

(I underline the good stuff, which I found particularly interesting, add links and images which I find suitable (for your viewing pleasure 🙂 ))

So, here it is:

=====Start of letter======

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Hearing Loss Demonstrator

I wish I came across this many years ago…

HearLoss is an interactive Windows PC program for demonstrating to normally hearing people the effects of hearing loss. With HearLoss you can replay speech, music and noise under a variety of loudness, filtering and masking conditions typical of hearing impairments. Best of all you can interactively change the settings and demonstrate their consequences.

hearloss

Description

The HearLoss program plays back pre-recorded audio samples of some speech, some music and some typical background noise, either singly or in combination. As it replays, three sliders control a simulation of the effects of three common consequences of hearing loss: loss in amplitude sensitivity, reduction in frequency range, and loss in spectral detail. Changes in the amplitude sensitivity slider changes the loudness of the sound, changes to the frequency range slider changes the upper frequency limit of the sound, while changes to the spectral detail slider changes the amount of fine structure present in the spectrum.

http://www.phon.ucl.ac.uk/resource/hearloss/

Suggestions for Use

This is one way you might use the program to demonstrate the effects of hearing loss to normally-hearing people:

  1. Start the music playing and adjust levels so that the audience can hear it clearly. Stop the music.
  2. Explain that deafness is not just all or nothing, but that hearing impairments come in various degrees.
  3. Play music and demonstrate loss in amplitude sensitivity to mild, moderate and severe losses.
  4. Repeat for speech. Point out that difficulty in hearing speech affects our social interactions – we can’t follow what is going on in a group conversation, for example.
  5. Explain that if hearing loss was just a loss in sensitivity, then we could restore peoples’ hearing with just an amplifier.
  6. Explain that most hearing loss is not just a drop in quantity but also a dop in the quality of sound perceived. In particular the kind of hearing impairment asoociated with old age has associated changes in frequency range and spectral detail.
  7. Play music and demonstrate what a reduction in frequency range means: at mild, moderate and severe levels.
  8. Repeat for speech. Point out that even if the speech were loud enough, the loss of high frequencies makes it harder to understand.
  9. Play music and demonstrate the consequences of a loss in spectral detail. The effect of this slider is like looking at an out-of-focus photograph – you can’t see all the fine detail. Get the audience to listen as you bring the slider back to normal – you should hear the signal getting "clearer".
  10. Play speech and noise simultaneously with sliders set to normal. Point out that the speech is still fairly easy to understand.
  11. Add a moderate loss of frequency range and spectral detail. The speech is pretty unintelligible now, although it becomes a bit clearer when the noise is turned off. Hearing impaired people find listening in conditions of noise far more difficult than normally hearing people.

Copyright

HearLoss is not public domain software, its intellectual property is owned by Mark Huckvale, University College London. However HearLoss may be used and copied without charge as long as the program remains unmodified and continues to carry this copyright notice. Please contact the author for other licensing arrangements. HearLoss carries no warranty of any kind, you use it at your own risk.

Vestibular disorder symptoms I have experienced

I came across an interesting website for an organization called VEDA (VEstibular Disorder Association).  I found this list of possible symptoms that is very interesting.

Image copied from “vestibular system.” Online Art. Encyclopædia Britannica Online. 23 Jan. 2008
Here is an explanation of the Vestibular system.

I did not initially place all these symptoms into the same category (i.e. having to do with my hearing), but maybe I should have??? I exctracted the whole list and will excempt (a strikethrough line) those not experienced by me. If commented, the comment has been marked like this.

This list was a revelation to me… It all fits, kind of… Seems it connects to the wiring of the vestibulo-cochlear nerve: the nerve that carries information from the inner ear to the brain. Also called the eighth cranial nerve, auditory nerve, or acoustic nerve. If the “recruitment”-theory in my previous article holds water, the information about these symptoms could also have some bearing on the subject of my condition.

Vision

  • Trouble focusing or tracking objects with the eyes; objects or words on a page seem to jump, bounce, float, or blur or may appear doubled
  • Discomfort from busy visual environments such as traffic, crowds, stores, and patterns.
  • Sensitivity to light, glare, and moving or flickering lights; fluorescent lights may be especially troublesome Very much so!
  • Tendency to focus on nearby objects; increased discomfort when focusing at a distance
  • Increased night blindness; difficulty walking in the dark Yes, have to find walls or points of support in order to be able to move, get a complete feeling of immediate disorientation
  • Poor depth perception

Hearing

  • Hearing loss; distorted or fluctuating hearing Well, that’s not exactly news…
  • Tinnitus (ringing, roaring, buzzing, whooshing, or other noises in the ear) Very much so!
  • Sensitivity to loud noises or environments Especially high pitch like childrens voices
  • Sudden loud sounds may increase symptoms of vertigo, dizziness, or imbalance Yes!

 

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Explaining the analogy: "Recruitment" of hair cells in cochlea

During my research into my own declining hearing- and health condition, I came across information about a phenomenon regarding hair cells in cochlea called “recruitment”. I strongly suspect “recruitment” is what happens to me. It certainly would explain a lot of the things that happen(ed) to me and my hearing and the fatigue…

(Most of the text that follows is copied from this page at hearinglosshelp.com and edited by myself for the sake of this blog and my readers.)

What is “Recruitment”?

Very simply, “recruitment” is when we perceive sounds as getting too loud too fast. How is it possible to hear too loud when the hearing in fact is vanishing, you may ask… Well, be patient with me and read on…

“Recruitment” is always a by-product of a sensorineural hearing loss. If you do not have a sensorineural hearing loss, you cannot have “recruitment”. In simple layterm this means that this condition only affects those who have a significant loss of hearing caused by haircell-damage in cochlea (mainly).

As a sidenote; there are two other phenomena that often get confused with “recruitment”. These are hyperacusis (super-sensitivity to normal sounds) and phonophobia (fear of normal sounds resulting in super-sensitivity to them). Both hyperacusis and phonophobia can occur whether you have normal hearing or are hard of hearing.

An analogy for understanding how “Recruitment” got its name

Perhaps the easiest way to understand “recruitment” is to make an analogy between the keys on a piano and the hair cells in a cochlea.

The piano keyboard contains a number of white keys while our inner ears contain thousands of “hair cells.” Think of each hair cell as being analogous to a white key on the piano.

The piano keyboard is divided into several octaves. Each octave contains 8 white keys. Similarly, the hair cells in our inner ears are thought to be divided into a number of “critical bands” with each critical band having a given number of hair cells. Each critical band is thus analogous to an octave on the piano.

Just as every key on the piano belongs to one octave or another, so also, each hair cell belongs to a critical band.

The requirements for “Recruitment” 

When you play a chord on the piano—you press two or more keys together but they send one sound signal to your brain. Similarly, when any hair cell in a given critical band is stimulated, that entire critical band sends a signal to our brains which we “hear” as one unit of sound at the frequency that critical band is sensitive to. This is the situation when a person has normal hearing.

However, when we have a sensorineural hearing loss, some of the hair cells die or cease to function. When this happens, each “critical band” no longer has a full complement of hair cells. This would be analogous to a piano with some of the white keys yanked out. The result would be that some octaves wouldn’t have 8 keys any more.

Our brains don’t like this condition at all. They require each critical band to have a full complement of hair cells. Therefore, just as any government agency, when it runs short of personnel, puts on a recruitment drive, so too, our brains do the same thing. But since all the hair cells are already in service, there are no spares to recruit.

Getting to the point – what “Recruitment” means

What our brains do is rather ingenious. They simply recruit some hair cells from adjacent critical bands. (Here is that word: recruit or recruitment.) These hair cells now have to do double duty or worse. They are still members of their original critical band and now are also members of one or more additional critical bands.

With only a relatively few hair cells dead, then adjacent hair cells may just do double duty. However, if many hair cells die any given hair cell may be recruited into several different critical bands, in order to have a full complement of hair cells in each critical band.

 

 

The results of the phenomenon known as “Recruitment” – the conclusion

The results of this “recruitment” gives us two basic problems. (notice the underlined parts!)

  1. The sounds reaching our brains appear to be much louder that normal. This is because the recruited hair cells still function in their original critical bands and also in the adjacent one(s) they have been “recruited” into.

    Remember that when any hair cell in a critical band is stimulated, the whole critical band sends a signal to our brains. So the original critical band sends one unit of sound to our brain, and at the same time, since the same hair cell is now “recruited” to an adjacent critical band, it stimulates that critical band also. Thus, another unit of sound is sent to our brains. Hence, we perceive the sound as twice as loud as normal.

    If our hearing loss is severe, a given hair cell may be “recruited” into several critical bands at the same time. Thus our ears could be sending, for example, eight units of sound to our brains and we now perceive that sound as eight times louder than normal. You can readily see how sounds can get painfully loud very fast! This is when we complain of our “recruitment”.

    In fact, if you have severe “recruitment”, when a sound becomes loud enough for you to hear, it is already too loud for you to stand.

  2. The second result of “recruitment” is “fuzzy” hearing. Since each critical band sends one signal at the frequency of that spesific critical band, when hair cells get recruited into adjacent bands, they stimulate each critical band they are a member of to send their signals also. Consequently, instead of hearing just one frequency for a given syllable of sound, for example, perhaps our brains now receive eight signals at the same time—each one at a different frequency.

    The result is that we now often cannot distinguish similar sounding words from each other. They all sound about the same to us. We are not sure if the person said the word “run” or was it “dumb,” or “thumb,” or “done,” or “sun,” or? In other words, we have problems with discrimination as well as with volume. If our “recruitment” is bad, our discrimination scores likely will go way down.

    When this happens, basically all we hear is either silence, often mixed with tinnitus or loud noise with little intelligence in it. Speech, when it is loud enough for us to even hear it, becomes just so much meaningless noise.

    This is why many people with severe recruitment cannot successfully wear hearing aids. Their hearing aids make all sounds too loud—so that they hurt. Also, hearing aids cannot correct the results of our poor discrimination. We still “hear” meaningless gibberish.

    However, people with lesser recruitment problems will find much help from properly adjusted hearing aids. Most modern hearing aids have some sort of “compression” circuits in them. When the compression is adjusted properly for our ears, these hearing aids can do a remarkable job of compensating for our recruitment problems.

Dreams with captioning?

Ever imagined getting captioning in your dreams? I received a question from one reader yesterday that made me analyze my way of dreaming.

The question was wether I hear sounds in my dreams or not, being almost deaf and having lived with hearing aids since the age of 4. As opposed to people who has been deaf all their lives, and report that their dreams has no sounds.

I couldn’t answer the question inpromptu, since said questioneer never left any contact-information, but hey, it’s an interesting issue and since I had a very vivid dream last night, I might as well make a little post of it 🙂

am_rapide_hi_30 The dream last night involved high speed car driving, a big explosion, some nature and various scenery (sort of like an industrial site, maybe an open mine). I can definitely say that I dream in colour! The car was a black Aston Martin Rapide, the grass was vividly green, the tarmac was black with white and yellow stripes on it and fences had a colour of metal (among other things).

As for sounds, most of the action was without sounds (no engine sounds, no screeching tires etc), but I dreamt that the car had a 26″ grenade shell (!) with it (plus a smaller one, for some reason). It was the kind of grenade that is loaded into huge cannons and it was compromising evidence that needed to disappear after a traffic incidence (because of the wild driving, I guess). So the car (with my son in it, for some reason) sped away from me after it had rolled sideways down a grass-slope. The driver needed to find a remote area where the grenade could be detonated and hence be disposed of…  (I know, it was a wild dream!!! 🙂 hehe )explosion-l

And this is where I get to wether I dream in audio or not. I dream in audio a little bit, because I remember that I heard the explosion (I did not see it), and started to run towards the origin of the sound.

So there you have it! Mostly I dream in facial-expressions, peoples actions, my actions (like running, trying to run, flying or trying to fly etc) and with colours. Not so much with sounds, although sometimes, and almost never (afaik) in actual conversations. I guess I’m a very “visual” kind of dreamer….

And no, I do not have dreams with subtitles, allthough that would be nice 😉

What I hear (or what’s left)

It would be a good idea for me to put down some kind of status as to how my hearing is these days (as a baseline):

Without my hearing aids I can barely hear:

  • My son singing at certain notes at the top of his voice (gives me echo-effect on that frequency until I hear new sounds)
  • A tractor right outside my windows (5 meters away)
  • Only the bass from music

keep-silence With hearing aids in quiet surroundings I hear:

  • Well enough to understand spoken words with the aid of lipreading (better if my head is clear and rested)
  • When really silent: a noisy refrigerator, traffic noise outside the building, an airplane or helicopter in the sky. I get a “white noise” sound from running water.
  • My external hard-drive – the spinning disks vibrate into the wooden table.
  • Other peoples voices in the room, but cannot understand without lipreading.
  • Familiar voices on the mobile for short conversations and messages. I most often have to repeat and ask for confirmation. It’s border-line.
  • Other peoples footsteps in same building, maybe a slamming door.
  • Static noise from electrical FM-devices like my Phonak Smartlink

With hearing aids in a “quiet cafe” surrounding I can hear:

  • Spoken word if not more than 1 meter away, but I have to concentrate really hard
  • Other people speaking, but cannot make out what is said.
  • Music, but only in the form of unrecognised sounds…

 With hearing aids in noisy surroundings I hear:1728

  • All sounds are garbled and mixed in an impossible soup of noise
  • I can extract a voice from 50 cm away if noise isn’t too bad, and I know the subject and the person (if I’m used to lipread whomever, it’s a better chance of understanding)
  • Cars and trucks travelling at high speed close by me
  • Dogs barking loud

When waching a movie with sound directly into my hearing aids I am dependant on captioning. Environmental sounds like running water (splashing), wind blowing, birds chirping etc are lost completely. Spoken words are not understood at all without captioning (dialogue is most often switching and camera angles changing too fast for lip-reading to be effective enough).

Music has lost it’s magic during the last few years. I can sense the rythm, and hear most of the bass and drums. Percussion is completely gone. Perception of vocals depends on type of music and what tone the voice has. Guitar has disappeared slowly last few years, now it’s not “swinging” at all anymore…

I wrote down this, because I want to use it to compare later when I get the CI (my personal baseline).