Before we get into the tech of soundproofing, let's address the cultural question, because that may inform our soundproofing goals.
Our population contains two distinct groups: humans, who have normal hearing, and werewolves, who have wolf-like hearing. These groups will have very different experiences, and so their cultures will have different trajectories.
Humans will not change their soundproofing habits, because they will be unaware of the fact that there are individuals in the community who can suddenly hear everything as though they're using audio surveillance.
Werewolves will not primarily experience this as a problem of "privacy," because their day-to-day experience will not centrally be about being observed by others, but of suddenly being able to observe all others. This maybe sounds like a cool benefit, but anyone who has lived in an apartment building can tell you that being forced to listen to the everyday noises of your neighbors grows obnoxious very quickly. It would only be enjoyable to a person who is nosy to the point of derangement.
So, what will happen is that each werewolf will very quickly decide that she must do something to silence the ceaseless clamor of her neighbors, or go mad. And as satisfying as it might be to simply murder the problem, she will also have to deal with traffic sounds, which will resist a "bloody solution."
Soundproofing tech has been around for a long time. There's interesting kinds of foam, and tiles, and fiberglass insulation, most of which can be done by a competent DIYer who is legally permitted to modify their residence. There's also a whole sub-discipline in architecture dedicated to acoustic design, but this is only relevant if you are extremely wealth and constructing a home (and my experience is that it's usually concerned with amplification, for performance venues and such).
But now we know that each werewolf's primary goal will be to dampen the noises coming from their neighbors, rather than to contain noises made by themselves. We also know that secrecy is of paramount importance to werewolves, because humans generally hunt and kill werewolves as dangerous predators, so each werewolf will be reluctant to do anything that might call attention to themselves such as ordering a pallet of foam soundproofing panels or ripping up all their drywall.
The ideal solution is the earplug:
- small and inconspicuous, can be concealed on one's person
- usually inexpensive
- can be used anywhere, not just in the home
- can be removed at any time when super-hearing is desired
- not cause for suspicion if discovered by humans or authorities
Earplugs have been around for a very long time. Apparently they were patented 140 years ago, in 1884 1, but even the ancient Greeks knew about plugging one's ears to stop noise (it is mentioned in The Odyssey, written nearly three millennia ago).
If you've worn disposable earplugs, you know they make everything sound muffled. Your werewolves can do better: a special variety of "Musicians Earplugs" was invented in 1988 which dampens sounds while maintaining clarity. These need to be custom-fit to the wearer's ears, and a pair costs about \$350 today; I'd guess they probably ran closer to $800 back in 1998. A cheaper version came out in 1990, so that could be a more affordable option.
Here is how I think things will play out:
- each werewolf will independently come to the conclusion they need to get earplugs or go insane; once they have good earplugs, they'll usually be so satisfied that they will stop looking for more extreme solutions
- as the population of werewolves grows and members learn to identify each other, they will start to compare notes about the noise problem and their solutions
- info about the best quality earplugs will become socialized among the group
- many of these werewolves will develop an amateur interest in what we humans call "hearing protection"
- any town with more than a few werewolves will develop a small business that sells unusually good earplugs and other home soundproofing solutions, which will be operated by one or more werewolves; it will also have free, quality literature about hearing loss, state-of-the-art hearing protection, and soundproofing
- at first there will be a slight increase in violent crime near the "ear shop," after which it will become one of the safest neighborhoods in town once the owner puts out the word that anyone becomes persona non grata if they draw attention by getting violent near the store
The werewolves who run the shop will be some of the most politically powerful members of the local werewolf community, because they will know the identifies of every local werewolf. They'll also be flush with profits.
Civilians who wander into the store are likely to pick up on an odd vibe, similar to walking into a mob-owned storefront (I did this once, I think, and it's a strange feeling). Local kids will definitely know about the store, and it will figure prominently in a lot of their rumors and spooky tales. Young people who grew up in town will be inexplicably very afraid to go into the store for any reason. Little kids who are in the area and need to urinate will rather pee their pants than go into this store to use the bathroom, and if their parents insist, the kid will unfailingly lose bladder control and wet themselves when their irritated parent reaches for the door handle; this will be such a frequent occurrence that local parents will gossip about it (before and after PTA meetings, for example).