Headphones do not inherently damage hearing. What's damaging, is listening to them at a high volume. This might occur if you're in a noisy environment, and use headphones with poor isolation, e.g. airpods, which need to overpower the ambient noise.
You can absolutely listen to headphones all day, in a quiet environment or if they provide good isolation.
2. 50% potential is a bold claim, but even if that were true it may still be economically wise to stick with the 50% penalty considering how expensive it would be to have a large number of employees with their own offices.
I'll also point out that the folks advocating for "collaborative" offices generally make "bold claims" with little evidence (or even argument, at times) to substantiate.
The point is that this is not a well substantiated position. Even if it is clearly demonstrated in some anecdotal cases (sales, marketing, tech support), there is a wide variation in what the day-to-day looks like within software development organizations. Keeping in mind, especially, that an open workspace for a small shop of 10 engineers is completely different than an open workspace for a floor of 200 engineers. And even moreso if there is a mixture of engineering and non-engineering (management, client relations, sales, etc.) on the same floor.
There are enough ins and outs in how work actually gets done that I'm skeptical that we can categorically say much about open floor plans. I'm sure they are more efficient in many cases. I'm certainly not granting the implied "always" or "often enough to be granted" in "they have such an economical advantage".
My default take for such things is that companies should be hiring experts and then trusting their expert opinions. Otherwise, I'm not sure what's the purpose of spending millions on presumably wise and intelligent engineers.
Insert "now you're thinking" meme image:
Sound can't hurt your ears
If it doesn't exist
> prevent your perception of sound.
No. It is destructively interfering with the wave. You don't perceive it because there is no more sound, not because of some perceptual trick.
(For any pedants looking on, I'm ignoring the fact that the cancellation may be imperfect. Unless there's actually constructive interference going on -- which is not what delinka is saying -- there is plain and simply less sound.)
It’s probably not as good for your hearing as an equivalent level of passive NR. When I fly long trips, I notice that my hearing is slightly impaired for a day or so. There could be a lot of confounding factors there, of course.
That's not added sound, though, that's a portion of the original sound that just didn't get cancelled.
You can also get ear pieces molded by an audiologist for some high end earbuds that will block out sound almost completely even if you're not playing any sound.