Zwicker effect

John H. john at faraway.com
Mon Jun 23 00:05:23 EST 2003


Tony,

Sorry for the late reply, my isp newsreader has this nasty habit of not
downloading some messages ... .

Tinnitus as external:

Thanks for the reminder! When my tinnitus first started I was studying at my
desk and could hear this low frequency rumble, like the sound of heavy earth
moving machinery. Living in a suburb I thought it odd to hear such a sound
so went outside to try and locate the sound, then realised I was only
hearing it in my left ear, the side which i experienced major problems after
neurosurgery which left me almost blind in right eye and probably some
diffuse orbitofrontal damage as well (4 years of age, right on the temporal
cusp, otherwise I might have become a sociopath but some might suggest ...
_). Studies have shown that people with head trauma have a higher incidence
of tinnitus on the side of the injury. One for the peripheral argument.


Allydonia:

Sorry, wrong word, I was referring to how some musicians end up with
twitching muscles in the relevant hand from too much playing. Actually this
may be either central or peripheral, debate still going on.

Glutamate:

Just another guess but premised on the above condition. As to auditory
restriction, idea came to me because of lowering synatpic thresholds from
continual stimulation (musicians playing loud music). However, tinnitus
tends to move around in terms of frequency so I take your point.

The other issue I'd like to raise here is that hearing has two primary
processes. Most sound is heard through non-amplification in the inner ear,
but there is a mechanism where some hairs are acutely sensitive to v. low
levels and will generate a signal when all these hairs become entrained,
then you'll hear something. So I'm wondering if tinnitus may relate to this
process rather than general hearing, which may explain why in many tinnitus
suffering overall hearing is not affected and the tinnitus only becomes
apparent during very quiet periods.

I suppose the other issue to consider here is that today we live in a very
noisy environment but our hearing evolved in relatively much quieter
environments. Hence the over stimulation idea.

Thanks agaion,


John H.

"TonyJeffs" <tonyjeffs at aol.com> wrote in message
news:8ec4c623.0306120337.5e070b56 at posting.google.com...
> "John H." <johnh at faraway.xxx> wrote in message
news:<3eddd462 at dnews.tpgi.com.au>...
>
> >
> > I don't like the "phantom limb" analogy because:
> >
> > tinnitus is experienced in the ear, phantom limb is sensation in space.
> > Phantom limb can involve pain, to my knowledge this is not experienced
in
> > tinnitus.
> > Phantom limb is a real sensation that makes sense to the experiencer,
> > tinnitus is more like random noise.
> >
>
> I get what youre saying - there's a deal of difference,  but tinnitus
> too is like a real noise sensation. Almost the same as having
> headphones on really. The only difference is that it is so absolutely
> fixed in location and pitch.  If you have headphones on, you can nudge
> them and the sound'll tweak a little reminding you that it's external.
>
>
>
> >
> > I accept that some tinnitus if of central origin. Reminds me of
allydonia
> > (spelling?) where some musicians experience uncontrolled spasms from
> > continual use, I wonder if excessive Glutamate activity lowers synaptic
> > thresholds to the point of over sensitivity. Raises the question, do
GABA
> > agonists help in this context??? Is there GABA receptors in the auditory
> > nerve network?
> >
> >
> > John H.
>
> Not heard of allydonia before.
> Glutamate...but if a neuron was defective in that way, wouldn't it
> either recover or die, and why would this condition predominate in the
> auditory pathway? (not disagreeing, I can find loopholes in everything
> I come up with too, so I'm just wondering)
>
> There's been some research into use of glutamate antagonists, and the
> guy 'selling the treatment'reports an 80% success rate, but a friend
> who followed it closely wasn't convinced.
>
> The other main neurotransmitter is ACh on the efferent pathway. I
> think that ACh antagonists do work. I've seen a lot of people claiming
> that various concoctions helped, where one might think it's indirect
> psychological help, but comments related to scopolamine strike me as
> remarkably convincing.
> Never tried it myself, though.
>
> Tony





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