Distortions that the human ear likes. Are there any ?

I guess the question comes down to: How do you like your truth?.

A touch of reverb almost always seems to be universally preferred. The so called singing in a tiled bathroom effect.

I wonder why? Could it be that it somehow makes us feel safer?

Or is it some otherworldly dreamlike quality that we like.

Even better than real life?

Perhaps that's why Pop music has been processed in some way or other for decades. Some of the artists have enjoyed more than a little vocal assistance.

Flanging, whammy bar, wah wah pedal, pseudo quadraphonic, equalization, Dolby, echo.

Without reading all of this...
Strings.  The pure sound is the strings.
A violin a cello (etc) only distorts the sound from the strings, as it bounces around a bit before we hear it.   "Pure" is physics, and I love physics, but emotions are anything but pure.  

Here's the problem: All electronics make significant distortion, even though on paper it looks 'low'. But what is on paper is pretty much the Emperor's New Clothes.
However, the ear has a masking principle and in audio its sort of come to our rescue. Solid state amps make considerably less distortion than tube amps but tubes are still around because solid state is harsh. This harshness is caused by higher ordered harmonics. The thing is, there is less distortion in the solid state amp than in a tube amp, but in a tube amp there are also more lower ordered harmonics- in particular the 2nd and/or 3rd (our amps favor the 3rd, which is treated by the ear very much the way it does the second).


The presence of the lower ordered harmonics masks the presence of the higher ordered harmonics. This is significant, because when masked the amp sounds smoother, even though it has more distortion. The funny thing is that it can also sound more detailed and have a deeper wider soundstage- and this is directly on account of the higher distortion! So what is happening is the lower orders are helping the otherwise high distortion amps to sound more real- and the ear's masking principle has a lot to do with it.

Now the other bit is that the ear is keenly sensitive to higher ordered harmonics. The reason is we use them rather than the fundamental tones to sense sound pressure. So the ear **has** to be sensitive in this regard. The fact of the masking principle is what makes *any* sort of electronics listenable.