Re: Binaural Upgrade

["Scott Fraser" scottbfraser]

<<A-weighting doesn't help noise figures as the thermal Johnson noise of
the air rises with frequency. That's the datum for self noise. BTW I
heard it once as a young teenager in a windless grassland and after my
ears had settled down for over an hour. My heartbeat was loud and I
could hear my pulse and behind that was a very high hiss.>>

I'm not a physicist but I believe the thermal (Johnson) noise  
limitation in recording chains stems from the molecular motion in the  
electrical conductors in every stage, from microphone through preamp  
to the ADC, rather than in air. The hiss audible in your grasslands  
experience has been described by researchers using anechoic chambers  
as a result of the human nervous system, which has its own signal to  
noise ratio.

Scott Fraser