At 09:19 PM 4/19/01 -0400, you wrote:
>Sounds to me like you are saying that whenever a molecule hits the eardrum
>on one side another one hits the other side simultaneously? I was talking
>about individual molecule impacts here. And no, "molecules rubbing together"
>was not mentioned. Molecular motion was.
>
>Again, I am not claiming the statement is true--that the sensitivity of the
>human ear being just short of being able to hear the impact of individual
>molecules--just that I read that in a textbook years ago.


I have been out of town for a few days and lost track of this thread - I
was at the WEKA conference at AZ State which included listening to quite a
lot of clavichord in a fairly large hall, which is sort of where this
thread got started.  Two things:  one is my own first conscious experience
of the phenomenon described by Owen a while back, whereby the effective
"gain" of my aural processing system got jacked up after a few moments of
intense focus, until the clavi sound went from being barely audible to
completely filling my ears.  The interesting this was that in this state, I
became very aware of the background noise inherent in said aural processing
system, which in my case consists of a high-pitched "hum."

At the reception afterward I got into a discussion with a pretty smart
electrical engineer who had also experienced this, and he said he had read
somewhere that in quiet surroundings it is "almost" possible to hear
"molecular motion" in the sense of thermal fluctuations, which is the root
basis of most "noise" in detection systems.  This is not quite the same as
hearing individual molecules, but more related to Brownian motion, which is
described in any good book on modern physics.  In fact, it was I think the
subject of one of Einstein's first published papers.

As usual, trying to remove some of the mystery, with variable success.  And
having missed a couple of chapters, I may be repeating what someone else
has already said.

JB



>Bob
>
>
>----- Original Message -----
>From: "Roger Clarke" <[log in to unmask]>
>To: <[log in to unmask]>
>Sent: Thursday, April 19, 2001 9:07 AM
>Subject: Re: Baldwin hpschd
>
>
> > Yes, but the point is that the forces each side balance; you need an
>imbalance
> > to get a finite diaphragm (eardrum) displacement. This, I suppose, could
>be
> > achieved by making the pressure on the two sides different. What you feel
>when
> > you have a bit of a cold and the seat belt lights come on for landing, for
> > example.
> > RJC,
> > Edinburgh.
> >
> >
> > On Wed, 18 Apr 2001 13:47:28 -0400 Robert Feeser
><[log in to unmask]>
> > wrote:
> >
> > > Well, I don't know that it is impossible. I remember in a psychology
>course
> > > reading that the sensitivity of the human ear was just short (by
>design?) of
> > > being able to hear the impact of individual molecules doing their
>Brownian
> > > motion dance. The point being made was that any additional sensitivity
>at
> > > the frequencies where we hear best would be counterproductive.
> > >
> > > Of course, I can't say whether that was true. But if so, it doesn't
>stretch
> > > my imagination too much to think that some sound pickups could be a
>little
> > > more sensitive than our ears.
> > >
> > > But when I read the subject message, I took the mention of molecules
>rubbing
> > > together as just an embellishment of the idea of background noise.
> > >
> > > Bob
> > >
> > >
> > > ----- Original Message -----
> > > From: "Roger Clarke" <[log in to unmask]>
> > > To: <[log in to unmask]>
> > > Sent: Wednesday, April 18, 2001 11:03 AM
> > > Subject: Re: Baldwin hpschd
> > >
> > >
> > > > O.K., but didn't he mention molecules rubbing together (sorry - I
>haven't
> > > got
> > > > the original mail)? I don't think that any sound pickup device can
>detect
> > > that.
> > > > RJC,
> > > > Edinburgh.
> > > >
> >
> > --
> > Roger Clarke
> > Computing & Electrical Eng.
> > Heriot-Watt University
> > [log in to unmask]
> >