Uilleand, Hi. Interesting ideas.

I have seen work suggesting that perception of colour has varied over human history, but it is something that simply cannot be investigated successfully. Even today, there is no way that individuals with full colour vision can be sure that they are seeing colour as others do. We may have differing proportions of colour receptors (there may even be differences between left and right eyes in the same individual). We can only communicate our colour vision by reproducing what we see in pigment or light, or by words. Clearly any differences in perception will be echoed by coloured examples of what we see. (Though in the case of colour blindness, odd choices of pigment would alert observers to the condition.) Equally clearly, words are a severe limit on communication of something like colour. In the first case, we can look at things painted in the past. Where it is possible to reconstruct the pigments, and to take account of changes due to age, people seem to have represented things with appropriate colours where they were available. The limits of language can impose misinterpretations. I have seen it argued that because Homer described the sea as wine-dark, the Greeks of his time could not see blue. Yet this depends on a child's understanding of the colour of the sea, not on true perception. The sea may be wine-dark at certain times and in certain places (I have a photo of sunrise or set which is). There has recently been discussion in, I think, New Scientist, of tribes in the Pacific which have a limited colour vocabulary. But limited vocabulary does not mean limited vision. English has many words for blues greens and reds, but few for yellow - we mostly distinguish shades by adding modifiers. The limits may arise from the limited range of pigments available in the past. We have no way of knowing precisely what people saw in the past, so we can't argue from that in any direction. I do remember a program about a child who had had limited linguistic stimuli in development, who was later educated, and was astonished to find that there were not different words for every shade of colour in a rack of threads. We shape our world by our words.

We are on more certain territory with sound, as ancient instruments can be found and played. Even Neanderthal pipes have been found and the tuning of those is fixed (apparently a full solfa scale, not modal), but I don't know about the changes you cite. Odd, though, as the higher frequencies are those we are more likely to lose early with modern noise pollution.

As to time speeding up, I know what that is. It's age. It really works to the advantage of a teacher, that one. Keep the little dears in for one minute, and it's an aeon to them, no time at all to one of us.