Nice post, especially for non musicians like myself.
There never seems to be enough easy to digest information on musical frequencies. Where exactly does bass start, and what's the difference between bass at 60Hz and that at 40Hz?
To make matters worse there's also the dreaded Fletcher-Munson curves.
According to the article linked below:
"Beyond just understanding this curve, it’s necessary to pay homage to the brilliant minds behind this phenomenon; Harvey Fletcher and Milden A. Munson.
In the 1930’s, the two researchers accurately measured, produced, and published a set of curves that showcased differences in the human ear’s sensitivity to loudness in relation to frequency.
The conclusive result of these curves also demonstrated that the human ear is most sensitive to frequencies between 3kHz and 4kHz."
I would have thought it would be a little higher, but there you go. It's amazing to think this work was done almost 100 years ago.