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Hi Dave,
In partial answer to the second part (of your query below), possibly
no-one has tested your thought explicitly because there is no reason to
suspect it would work. At the same time, the transducer mechanisms of
ears in various animals are now quite well understood: what's know
doesn't suggest that the sensory receptors (one type of hair cell) are
specialized for RF detection, while they clearly are specialized for
mechanoreception. Perhaps the most obvious thing is that people who
have offices or apartments right next to cell phone relays or
broadcasting stations would start to "hear" the radiation directly, if
your suggestion were true -- they wouldn't need a radio. And you'd
hear every lightning strike at light speed, not just via the
sound-wave rumble of thunder seconds later.
The RF energy would be extremely low unless you were standing right
next to a transmitter; it's not clear why this would have evolved in
the first place because no animals including us use this form of
communication; to use it you would have to have some effective form of
transducer like your crystal radio, and none is known; most forms of
external stimulus transduction are beset by 'noise' and use some form
of early amplification to partially overcome this, and there is nothing
obvious in the ear that suggests an RF amplifier, while it is well
established that our ear contains a fairly potent pressure amplifier to
juice up the sound pressure changes.
The actual transducer mechanism is known to reside in some of the
cilia ("hairs") that stick out of one side of this one type of hair
cell, and which contain small numbers of mechanically sensitive
membrane ion 'channels' that are shut when it's quiet. When the cilia
are displaced mechanically by a sound-activated travelling wave on a
nearby membrane that originated as a pressure wave at a 'window' in the
ear, little molecular strings called tip links pull on the channels,
which open and let millions of ions flow through. This changes the
voltage across the hair cell's main membrane. This story is simplified
and doesn't deal with frequency tuning, but it's this voltage change
that causes neurotransmitter chemicals to be modulated at the nerve
connection from the hair cell to the auditory nerve. This in turn
causes changes in impulse firing in that nerve, which after some more
steps results in more nerve impulses further up, which finally get
interpreted centrally as sound.
Having said this, it is certainly not outlandish to suggest that
some other form of energy might be the proper stimulus, and that
convention has got it wrong, because this has happened historically.
The classic case is not far from your idea, of electroreception
(detection of very weak, water-born electric currents). This is a
sense completely foreign to us, that some fish species use for
signalling, object and prey detection. The electroreceptor sense cells
historically went through a sequence of being misinterpreted as to
their function, at one point being suggested to be temperature
receptors for instance. People in these fields are now sensitized to
the need to define the actual natural stimulus used by that system,
rather than something that also affects it but that's just an
epiphenomenon.
Steve
On 8-Nov-06, at 3:09 PM, David & Alison Webster wrote:
> The article also mentions in passing the enigma of sound generation by
> northern lights. I have read elsewhere that attempts to record sound
> produced by the northern lights have recorded only silence [and in
> another context, cannon roars recorded for the 1812 Overture by
> conventional methods sounded like a soap bubble bursting]. Many
> people, including yours truly, have heard the northern lights so one
> must ask what form of energy is being 'heard'.
>
> Is it possible that inner ear papillae can act as detectors for high
> frequency radio waves generated by electrical discharges ?
>
> Yours truly, Dave Webster, Kentville
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