On the subject of subvocal microphones, micro-transceivers, and commlinks, my view of micro-transceivers hews pretty close to Herr Brackhaus’. My reading of the rules was that they’re communication devices notable or useful because they let you communicate “around” the Matrix, using radio waves instead of whatever wacky magic Matrix signals things normally use. Someone could speak into a micro-transceiver and a commlink-user on the other end could receive the message (“it just lets you communicate by voice with other micro-transceivers and commlinks that you (and the other person) choose, within a kilometer” PG. 441 for core)… but they’d need to be tuned to that micro-transceiver’s frequency, which is not something you could find out/hack/spoof with the Matrix, because these are radio waves and very pointedly not the Matrix. Basically it’s a more secure method of communication that doesn’t rely on the Matrix at all.
Micro-transceivers also include a subvocal microphone, so you can think of it as an upgrade to a subvocal mic. Subvocal communications definitely don’t require headware (not quite sure where you’re getting that impression). It’s just a microphone sensitive enough and tuned to pick up very quiet whispering. People can still overhear you and it requires you to physically whisper, but listeners get a -4 to overhear your stage-whispers.
So to summarize:
Subvocal Microphone: Part of a micro transceiver or an add-on to a commlink that lets you communicate subvocally. Meaning your whispered speech comes in loud and clear to the other person on the other line (or alternately you use voice-to-text to turn your whispers into text messages for your team).
Micro-Transceiver: A subvocal microphone and earbud that communicates via radio waves. This is significantly less likely to be hacked or overheard than standard Matrix communication. Micro-transceiver users can communicate with commlink-users and vice versa, though the commlink users would essentially need an “invite” from the micro-transceiver guys with the correct radio frequency.
Commlinks: The super-smartphones we all know and love. A commlink with its wireless off (not just running silent, but actually shut off via the Matrix) would still be able to do plenty; you could play downloaded games with it, use downloaded applications like calculators or a flashlight or something, but you very notably couldn’t communicate with anyone with no Matrix access. They’re built for Matrix communication, basically. Though they can send and receive radio signals, basically all their communication functions shut down once they’re unable to access any Matrix grids (this would be the 6th world equivalent of “no bars”).
That’s how I’m going to run it, provided it makes sense to everybody. Hawkeye can use her micro-transceiver to send messages to her teammates, but they’ll either need to pick up that communication on a micro-transceiver of their own (though you’ll be limited to audio only… micro-transceivers don’t have all the AR bells and whistles of a commlink) or pick it up on their wireless-enabled commlink. Sound good?