I don't dispute any of that. What I don't buy, however, is that there's some electronic conspiracy among sound engineers to make women's voices sound bad. I don't buy that powerful female artists (like Madonna) would put up with that. I don't buy that the record companies, who want to sell those records by female artists, would put up with that.
Lastly, if it takes a highly trained ear to pick up differences, then the difference is not material to the public and it's an ineffective conspiracy (assuming there is one).
> What I don't buy, however, is that there's some electronic conspiracy among sound engineers to make women's voices sound bad
It's not claiming "conspiracy" stating the facts that the sound transmission was almost always not optimized to produce best result for female voices and that male voices were more lucky. I studied electrical engineering and I can confirm that the simplified claims were taught as:
"voice frequency is 300 to 3400 Hz"
which effectively misses the higher frequencies that unfortunately disfavors understanding of female voices, but nobody learns that detail there:
or that most of the products sold for music also disfavor female voices versus the "bass effect" -- you'll find infinite amount of "bass boost" speakers and earphones (even those that claim they don't typically do that) and much less (I couldn't find any where it's even stated as a goal of the design) those that allow the best understanding of voices instead of distractedly "pumping" the bass line.
Using Madonna as an argument is weak. Compare how much actors earn compared to the actresses and how much actresses ever could influence the movie industry result. Music business is similar -- female artists are surely limited in what they can achieve regarding how their music is being played, and they surely can't change the preferences of the whole industries. I guarantee you that female voices come worse than they should even in modern times and especially in movies and TV (not in pop music) and that it can be easily heard by anybody who is interested in the topic.
Do your own research about what the "industry" spreads as a "common knowledge" and "what people want" as of today -- it's never real fidelity or a linear response. It's primarily "how can music sound louder than the competition." And "more bass."
Decades ago I knew an old sound engineer who always carried around his own amplifier and earphones to compensate his hearing loss. He was showing me his own measurements (graphs), and how almost everything claiming by the producers of the earphones were lies (exactly regarding fidelity). He worked really hard to select the earphones that worked "correctly enough".
Lastly, if it takes a highly trained ear to pick up differences, then the difference is not material to the public and it's an ineffective conspiracy (assuming there is one).