Topband: cw pitch

[Jim Jarvis]

The brain is an amazing signal processing system.

Depending on the statistical nature of the prevailing
noise, you may hear better with a lower freq. OR with a
higher freq.  It isn't always the same.

Moreover, despite our tendency to use tight filters,
they may not be the best for small signal detection.

Two reasons:  

First, the brain needs a fair statistical 
sample of the noise, to be able to hear things against it.
A narrower filter may not provide enough noise input for
effective 'cancellation'.  Not the right word...may be
'selection' or 'differentiation'...but you get the idea.

Second, narrower filters may have ringing and phase distortion,
which confuse the brain...such that the s/n r is NOT improved
with the narrower filter.  I often found this to be true with
my old 756PRO.  Widening back out to 1KHz and shifting to a higher
pitch brought the desired signal out of the noise, even though
I prefer listening to 400Hz or lower.  

The message is...try both approaches before you give up.  

N2EA