[sdiy] The eardrum and brownian motion

[Dave Krooshof]

>My thinking is that all sound is "dithered" by the Brownian motion of the
>air itself. Is it possible this is why digital mastering software needs to
>add noise back into a noiseless signal in order to improve the sound?
To my experience only whan sound is fed to the brain via UW-SCSI
or firewire. Other routes are noisy enough by itself.

Seriously, I hear dither just as what it is: Noise.

>>if one stays in a completely dead room i.e.
>>anechoic chamber, after a few minutes it starts to
>>freak you out.
Can be three things:
1 and 2: your blood and neural activity now audible due to lowered treshold,
or (3) your conciousness :-)

>>you  will be able to hear your heart beat and the flow of blood through
>>your fingers.
As well as the louder noise of your arm muscles. Your arm-positions
are balance by rather low-rate pulses. A low noise is the result.

>>Never knew it came from the nervous system,
>>somehow it feels a bit scary to hear your own nerves.
>>Mmm, would the noise change character depending on ones mood?
Yes. And stress + coffee too.

>>Back in the '70's i was able to spend a good deal of time in a studio
>>that was light tight
low light frees up room in your brain to calculate audio, so it seems.
Ever noticed how much you lower your stereo when you dim the light?

>>Your (or at least my) ear starts to "auto-range" as if it is
>>"searching" for sound.
That can be true, it fits theory as well as my perception.
That's also the beep you hear when a hair in hour ear is bent.
The beep is the membrane being vibrated by the ear to check out
what sound it causing the hair to be bent. You can pick up this
sound with a microphone.
When the brain decides there's no real sound, a complete set of
hairs is shut off!
>>Notably, i did not hear a "high pitched" squeal or tone.  Anyone
>>subject to this may consider being tested for tinnitus.
eew.

>>Here's a notion I have had for a while. The ear can
brain can
>>tell the shape of the room just by the ambient noise.
>>You can tell is you're in a cave just by the sound.
>>Perhaps this is a leftover survival trait? Kinda like
>>bat echo-location? If so, then ambient noise levels
>>would affect the ear's ability to do this, and lack of
>>noise would disable it completly.
My studio is pretty silent. Singers tend to feel
empty, lacking energy, and feel lonely.
It helps when I set up some shields. So I guess
you are right.
So if refections are absent, it's more or less
the same as the needed noise is absent.

Biologically it's true as well.
The sideline system of a fish is a groove over the body
off the fish, with little hairs in it. Noise from swimming in the
water is reflected, it bounces of stones, mates, preditors and
other items. This system was rolled up and put in our ears,
the 2 bones were 2 of the 4 form the operculum. (english?)
Interestingly enough, it was rolled up including the seawater,
so there's still slightly salted water in our cochlea.
It's #1 function is still: "Where is what?"

Synthesizer noises are nicely alien in this system.
It that why we add reverb? So at least this synthsound is somewhere?

>>That could give new meaning to the term "warm" :-) But I'd think your
>>ear would hear the same Brownian noise (if any) regardless of whether
>>it is listening to analog or digital.
Wow. cool twist.


Dave
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