[CQ-Contest] Filter???????

[Tony Rogozinski]

I've noticed something for years and just wonder if anyone else has the same experience?  This morning I was copying
OH6AH on 40M LP but he was pretty weak and the background noise made it a little difficult.  The speaker was on and
I needed to go downstairs to get something - as I descended the stairs it seemed like a filter was switched in by my
brain and all the background noise went away leaving only the signal.  Just like a nifty audio filter.  In years gone by
I have noticed this many times but never asked anyone about the phenomenon.  In Arizona I would be working in the
yard maybe 100' away from the shack, the window would be open and radio on and I could copy weak signals without
any problem.

Comments?????

Tony W4OI/HK1AR