That’s because you don’t have “essing.” You just have a really bright microphone, and you should try to solve this at the voice/microphone stage, because fixing it in Audacity in awkward and never sounds quite perfect.
First thing I did was Analyze > Spectrum and I found an artificial “haystack” or boost starting around 3000 and ending around 11,000. You can drag the analysis window larger to make it give you more information (attach 1). I figured out the approximate sizes of the haystack, just by looking. No fancy tools. About 12dB tall, about 3000 to about 12000.
Then I ran Effect > Equalization and created a reverse haystack (attach).
When I applied the correction, most of the brightness went away leaving a natural sounding voice. If it’s still too bright, you can make the equalization deeper (top to bottom). If you want, I’ll try to remember how to export the curve so you won’t have to make it yourself.
Real “essing” is when the sound crashes whenever you hit SSS. It actually turns into a different sound like listening to a military air traffic controller crashy voice as an extreme example. A De-Esser tries to recognize that damage, suck out the crash sound and substitute what it thinks your voice would have normally sounded like. Yes, it’s a bit of guesswork and it’s never perfect, that’s why it’s good to produce a clean track right at the top.
We have two conflicting ideas. Anything with USB in the title generally means that the sound is fixed once it leaves the microphone. All the sound shaping, amplification, noise compensation, etc, etc, is handled in the head of the microphone (the analog part) and that’s the way it is from that way forward.
However, I’ve never seen a microphone with that much of a blatant haystack seemingly all by itself in the microphone personality. There’s no way that would ever sound natural in a performance.
Scene shifts to:
A second microphone that also appears to be too bright and sharp. Now it’s different. A Yeti is not a terrible microphone and that points to Windows doing something to “help you.” It is Windows, right? Macs tend to not have these kinds of problems.
So. Dig in the Windows setups and see if it isn’t running something like a “Vocal Clarity Filter” (I’m making that up) or some special effect. We know Windows has Advanced Services what can try to remove noise from your voice while you speak like a cellphone does. This can improve communications or conferencing. However, Windows Enhanced Services hates music…
See what you turn up. This sharp, piercing effect is not normal.
I’m not horrified you’re using that little microphone. I’ve done temporary tracks (carefully) with the little microphone in my laptop and have used other microphones “against-type” when I needed to. I just didn’t tell anybody what I was doing.