The poster was concerned about the "man stopper" (self-defense is presumed), ability of the different .357 loads. Saving one's hearing at the expense of one's life (you would only shoot them with hearing protection in any other scenario, including practice), seems a tad short-sighted.
Short-sighted, I don't think so. 9mm and .45 will get the job done just as well as the .357 and still save your ears in the process. I used to carry a model 60 in .357, fired a round without ear protection once and I am left with tinnitus in my left ear and high frequency hearing loss. 9mm and .45 can certainly cause hearing loss, but not on the levels of the .357 mag.
any cartridge fired in a handgun is so far above the normal operating range of human hearing any small difference is inconsequential. As far as your ears are concerned there is no difference between 120 db and 125db
True any cartridge can cause hearing loss, but to say there is only a small difference and that your ears wont know the difference between 5db is wrong. A 3db increase is double how loud a particular round is and how we perceive it. I think someone is less likely to know if they got shot with a 125gr 9mm vs 125gr .357 compared to a several DB increase in a particular round.
1 dB = increase 26%
2 dB = increase 58%
3 dB = double
4 dB = 2.51 times
5 dB = 3.16 times