-wi' works somewhat like -er in English (teach / teacher ) Am I right ?
Yes, pretty much.
And like English -er, it's not restricted to people. Compare e.g. "toast / toaster": a toaster is a thing that toasts rather than a person who toasts.
Similarly, a QumwI' is a communicator, usually meaning the device you communicate with, though it could also mean a person who communicates.
Qov, the female recording of the sentence doesn't have a very strong v. Just taking dictation I typed out be' ghobe' SuvwI'. A second listen did not clarify any. I had to go through the early vocabulary in my head to figure out that it mus be ghovbe'. Even then I still couldn't hear the v when I played the audio again. It ate up valuable time on a timed test.