On (a), the distortion arising from electromechanical systems tends to be mainly second harmonic, which people don't seem to mind. It gives a sine wave some "body" or "warmth".
Badly designed DACs tend to produce third harmonic distortion, which sounds "harsh" or "bright" (= like a cafe with lots of hard surfaces and people crashing their cutlery around).
There are very few badly designed DACs being manufactured any more, but the loudness wars have made music sound both bright and "lifeless" (lacking in dynamic range).
So yeah, (b). (B) has been found to be the case even among people who make audio equipment for a living. People hear what they expect or want to hear, just like with vision.
Edit: main reference: Floyd Toole, Sound Reproduction. Toole worked in an acoustics research lab for a Canadian government, and then ran Harmon Kardon's research lab for many years.
Badly designed DACs tend to produce third harmonic distortion, which sounds "harsh" or "bright" (= like a cafe with lots of hard surfaces and people crashing their cutlery around).
There are very few badly designed DACs being manufactured any more, but the loudness wars have made music sound both bright and "lifeless" (lacking in dynamic range).
So yeah, (b). (B) has been found to be the case even among people who make audio equipment for a living. People hear what they expect or want to hear, just like with vision.
Edit: main reference: Floyd Toole, Sound Reproduction. Toole worked in an acoustics research lab for a Canadian government, and then ran Harmon Kardon's research lab for many years.