[Laser] Interesting Question.

[KD7JYK, 49H7KR]

Well, it's pretty off the wall.

For several years I have heard a hum, fairly low in frequency, it can be
likened to a diesel truck idling, and at times like a heavy truck lugging up
a hill.  After several months of testing, it seems to be an nervous system
interaction.  I hear it above certain light intensities, and closing my eyes
makes it go away.  Different colors seems to create my "hearing" of a
different tone, for example, looking at a red light is a nice pleasant low
tone.  A yellow light is a higher tone, still musical in nature, and green
lights create a hissing shrieking sound, like a cross between hissing steam
and a whistle with a ball in it such as used by police.

To sleep I use earplugs.  This would indicate an unknown accoustic source,
however the hum is heard world-wide which again points to nerve damage or
interaction of some sort.

Also over the past few years, I have noticed in fair lighting, especially
after watching TV, after I turn the TV off, I see a flickering in my eyes,
such as is seen with older film porjectors.  I always assumed my eyes had a
fairly fast response rate and were responding to the frame rate of the TV
images.

This morning I awoke and heard the hum while still wearing the earplugs.
This has never happened.  I closed my eyes, the hum went away, I covered my
head with my eyes open and it went away.  I pulled the earplugs out and I
heard the hum.  What is most interesting, is as I lay on my side looking at
where the floor and wall come together, I saw the flickering which only
occured after watching TV in the past.  The hum and the flicker I was
coincided perfectly.  I think there is some sort of nerve damage or
cross-wiring which creates the "hearing" of colors, but seeing the flicker
at the same time caused me to ask if there is something out there in the
light spectrum that is the equivelent of a low frequency hum that is most
always there, sort of like in an office building, sometimes you always hear
a hum from the HVAC equipment under the usual changing noises, just a
constant background drone, nearly always the same frequency.

I am wondering since I most always hear this hum which interacts with the
eyes being open, is there a constant pulsating light source that "hums",
something from the sun or a constant manmade light "din"?

I had an idea, a PV cell or CDS cell wired to an audio amplifier, I could
place it where I saw the flickers and see if anything can be heard.  This
should narrow down the question of it being just nerve damage, but thought
I'd ask here, just in case.

Just some ideas.

Kurt

Rosetta Proving Ground, Nevada
Hell's Laboratory