This bit that 'we' don't have the ears or mindset or environment of those
listening in the earlier centuries:
As you, I think, implied, we all NOW have different mindsets enough so
that we argue about everything we hear in performances.

But what stands out is that a vast majority of audiences today have shown
that they prefer the sounds of older instruments in the older music and
also prefer some of the stylistic approaches based on smaller phrases that
came out of the physical use of those instruments and from instructions in
treatises of that time.

It doesn't matter that we're in the 20th C vs the earlier audiences,
it's that IN SPITE of the fact that we are used to symphonic sounds, so
many of us find ourselves preferring early music played with the earlier
instruments and in less long-line undifferentiated style than that
exemplified by earlier players who played music of all eras as if they
were all written yesterday in the same sound environment.

So, the EARS thing with respect to different centuries just doesn't mean
much when the curious thing is that so many of us living in this century
are more comfortable with and are more drawn to the sound of the earlier
instruments in music of their time.  I'm more interested in why that is.

Andrys in Berkeley
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