Painfully loud sounds RE: AUDITORY Digest - 10 Nov 2004 to 11 Nov 2004 (#2004-237)

[Mortz <mmortz@xxxxxxx>]

Re:  feeling of pain associated with cochlear hair cell loss.

I have a bilateral sloping hearing loss.  One ear has a severe to profound
hearing loss and the other moderate to severe.  Above 5000 Hz, there is
almost no response in either ear.  Both ears have significant "recruitment";
i.e., "abnormal loudness growth", but the left ear with the worst loss has a
more dramatic problem.  This type of hearing loss includes both outer and
inner hair cells.  In my case, it is a cumulative effect of childhood
measles, mumps and adult Meniere's disease.

Loudness Perception:  A 80-85 dB sound to me is loud.  This is common with
people with more severe hearing losses.  Many people with this kind of
hearing loss perceive loudness growth as much or more than normal ears, once
it is above their threshold.  It makes fitting hearing aids more
complicated, because the useful dynamic range is reduced.  Compression
hearing aids are beneficial.

Pain Perception:  If there is a sudden loud sound (>95 dB for me), the pain
is very sharp and quite painful. It leads me to grab my ear to block the
sound and try to get out of the environment very quickly. The pain is
located in the ear region. My more damaged left ear feels pain more than the
less damaged right ear.

Speculation:  

The loss of outer hair cells destroys the feedback mechanisms that control
adaptive cochlear filter bandwidth, loudness summation and other
contributions to loudness perception. Pain might indicate abnormal upward
spread of activation and abnormal loudness summation effects.  The loss of
automatic gain control from the outer hair cells may lead to
over-stimulation of the remaining inner hair cells.  Perhaps this might put
stress on the tympanic membrane.   The hair cells themselves may be weakened
and not attach correctly to the membranes, making them more susceptible to
pain.

Theoretically, another potential factor might be excess endolymphatic fluid
due to Meniere's disease.  Often people with Meniere's disease (including
myself), tend have significant recruitment and find louder sounds painful.
However, I have doubts about the fluid pressure being the principal
contributor to pain.

My left ear had vestibular neurectomy surgery to reduce vertigo from
Meniere's disease.  As a consequence of this surgery, there is not supposed
to be a buildup of endolymphatic fluid which could put pressure on the
tympanic membrane.  However, given that I still feel pain in the surgical
ear, I don't think fluid pressure is the main reason.


"Margaret Mortz, PhD "  <mmortz@wsu.edu>

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Date:    Thu, 11 Nov 2004 18:38:16 -0500
From:    "Didier Depireux, PhD" <ddepi001@UMARYLAND.EDU>

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Subject: AUDITORY Digest - 10 Nov 2004 to 11 Nov 2004 (#2004-237)

There are 3 messages totalling 85 lines in this issue.

Topics of the day:

  1. estimate of frequency response (2)
  2. painfully loud sound

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Date:    Thu, 11 Nov 2004 14:55:55 -0000
From:    "Sean.O'Leary" <Sean.OLeary@UL.IE>
Subject: estimate of frequency response

Hi,
I want to estimate the frequency response of a violin and  guitar body, so
that I can examine the excitation spectrum.  The only method I have at my
disposal is that of recording the body response to an impulse, i.e. tapping
it.  I would greatly appreciate any advice on optimising this estimate.

Thanks,
Sean.

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Date:    Thu, 11 Nov 2004 11:32:58 -0600
From:    David Prince <dprince@ACOUSTICEXPERTISE.COM>
Subject: Re: estimate of frequency response

I'd recommend first reading up on Jurgen Meyer's Book, Acoustics and the
Performance of Music or the papers that preceded.

In doing room measurements with a violin as a source radiator (for realistic
directivity response) I had most luck using a shaker on the bridge of the
violin and using a sweep.  At the time I was using TEF but any chirp and
deconvolution method should work well.  I had trouble using MLS as a
stimulus.  A brief writeup of my methods can be found in the prodeedings
from the ASA Sabine centennial.

Good Luck,

David Prince

 >Hi,
 >I want to estimate the frequency response of a violin and  guitar body, so
 >that I can examine the excitation spectrum.  The only method I have at my
 >disposal is that of recording the body response to an impulse,
 >i.e. tapping
 >it.  I would greatly appreciate any advice on optimising this estimate.
 >
 >Thanks,
 >Sean.

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Date:    Thu, 11 Nov 2004 18:38:16 -0500
From:    "Didier Depireux, PhD" <ddepi001@UMARYLAND.EDU>
Subject: Re: painfully loud sound

On 11/9/04 7:56 PM, "jan schnupp" <jan.schnupp@PHYSIOL.OX.AC.UK> wrote:

> nociceptive pathways and pain) I wondered: what determines whether we
> would consider a particular sound to be painfully loud?

I don't remember what it feels like to feel a "painfully loud" sound
(whether it is felt inside the head, or just in the ear in general), but
wouldn't the tympanic membrane itself be a good candidate for the pain
sensation? The tympanum is innervated by four of the cranial nerves,
providing general sensation through trigeminal, facial and vagal cranial
nerves on the outside surface and glossopharyngeal nerve for the inside
surface.
I guess this might be partially answered if I knew whether people who lose
their hair cells still perceive loud sounds as being painful right after
hair cell loss, even though they might not perceive the sound as being that
loud?

                                    Didier

__
Didier A Depireux      ddepi001@umaryland.edu   didier@isr.umd.edu
20 Penn Str - S218E http://neurobiology.umaryland.edu/depireux.htm
Anatomy and Neurobiology                 Phone: 410-706-1272 (lab)
University of Maryland                                 -1273 (off)
Baltimore MD 21201 USA                         Fax: 1-410-706-2512

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End of AUDITORY Digest - 10 Nov 2004 to 11 Nov 2004 (#2004-237)
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