Yeah, I remember I never got my HAM license back in the day because of the Morse requirement( which is no longer needed). The human ear can use some sort of "Quantuum Superposition" on the sound, and filter it to clarity. The listener has clues when a poorly sent letter is received, like does it fit into the word correctly, does it make sense, etc? The listener "knows" what to expect, and what is "reasonable". This is all tough to do with computer logic.... computers are fast, but they are not reasonable. :-)