sound synthesis stuff

I've been reading over Tuning, Timbre, Spectrum, Scale, and doing some
examples, and have a question.

In appendix E it gives a formula for dissonance of two pure sine waves,
but no particular explanation of why that formula should be the way it is.
Are the exponents used based on some abstract idea, or are they simply the
result of measurement? Also, I seem to recall it saying in roederer that
the region of dissonance is farther away and wider in bass notes. Is that
correct?

-Bram

(Much happier now that he's realized all the math is to be found in the
appendices, was having trouble finding it before.)