This makes sense for smaller, close knit stations where it's assumed that everyone has met up with each other in some sort of pre-round orientation meeting. But in a 60+ person scenario, it begins to make less sense. I certainly don't know the voices, much less the names, of everyone I've worked or gone to school with.
The familiarity system would be a simulation of this. As people speak, you gain familiarity with their voice.
- If you are unfamiliar with someone and they're not wearing an ID, they'll show up as Unknown.
If you are unfamiliar with someone and they are wearing an ID and mask, their voice will show up as their ID.
If you are unfamiliar with someone and they are wearing an ID without a mask, their voice will show up as "Unknown (As ID Name)". (It's assumed that IDs are photo ids, so you'd be able to tell that bald dude with a mohawk isn't Zoey Webb).
If you are familiar with someone wearing a different ID, they'll show up like they currently do, "RealName (As ID Name)"
Radios kind of mess all this up I guess, something would have to be done so that chat isn't just 100 Unknown people. Handwave it as radios having facecams? :^)
Basically, you'll be familiar with people who you've heard often. This will likely include your coworkers and people you've chatted with. This will also include people who you've heard over the radio often, even if you haven't spoken to them personally. Therefore, trying to pose as a clown who has been very vocal over the radio advertising his clown mart would be difficult. Posing as an antisocial maintenance-lurker assistant? Well, that's simple.
Now, the current speech system doesn't handle people disguising their voices. Even if you know someone pretty well, they can still disguise their voice to make themselves sound differently. There would be a Disguise Voice/Speak Normally toggle, which would make your speech count as unfamiliar even to people who are familiar to you. However, ʏᴏᴜʀ ᴛᴇxᴛ ᴡɪʟʟ sʜᴏᴡ ᴜᴘ ɪɴ sᴍᴀʟʟᴄᴀᴘs, ɪɴᴅɪᴄᴀᴛɪɴɢ ᴛʜᴀᴛ ʏᴏᴜ ᴀʀᴇ sᴘᴇᴀᴋɪɴɢ ɪɴ "Tʜᴇ Bᴀᴛᴍᴀɴ Vᴏɪᴄᴇ".
Overall, the system would add depth to disguising allowing better random muggings and other Antag -> Victim communication, and would give an incentive to small talk with your fellow crewmembers hopefully leading to more total interaction and roleplay.