When I’m actually listening to music, only earbuds will work for me. I suppose I could try to get earplugs that look like decoy earbuds.
However, if your comment was meant seriously, i.e. that employees should do some noise-cancellation arms race song and dance with employers, that mildly terrifies me. How could any person actually think that it’s acceptable to let your employer treat you that way? It’s insane.
The actual best option is to first do excellent work that makes your employer respect you and really count on you to such a degree that firing you for expressing reasonable preferences is not realistic for them. Then once you have established that bar of credibility, find the right ways to constantly remind your manager and other managers that the workplace conditions are unacceptable. This requires political tact because outright grumbling or long-winded feedback sessions will be used against you. Rather instead, you have to find key moments to unassailably undermine your boss by visually demonstrating just how hard you’re working but keep pointing out that because of noise and distractions, nobody (not even good, old trustworthy you) can get the thing done on time or get the full set of features implemented, etc.
You have to convert your pain into your boss’s boss’s pain, or it will never change. Capitulating with headphone contortions is a terrible approach.
But in tech companies it’s all about optics.
It’s 100% about virtue signalling to management. Headphones fit the visual stereotype of a hacker, so it’s OK. Ear plugs carry a connotation that the stuff generating noise is somehow “a bother” or “a nuisance” ... which of course is true, but you’re not allowed to actually acknowledge that truth.