so, i keep getting dead-air calls from different 971#s... 971 is a local cell area code, i think usually for throwaway type phones.  i have no idea who this is but figure its probly all the same origin.  maybe yet another debt collector for some phony trumped up debt we do not owe.  if i accidentally pick up, its dead air.  otherwise i ignore and they leave no message.
971-235-8481
971-300-7779
971-285-7676

I called each of your numbers.
First one (8481) got an answer from a woman but it was a little strange.  It almost sounded like a computer voice?  Maybe just a poor connection.  
Second one (7779) rang 15 times before I got a message "...the wireless customer you have called is not available."
Finally (7676) rang about 4 times, woman answered and I feigned a wrong number.  Sounded pleasant.  Wished her a happy new year.  

Of course it's possible that a single person or some unethical business is spoofing the numbers.  Or it may just be wrong numbers or bad connections.

Hope this helps.  Happy New Year.

that was nice of you.
the 7676 # called again just now on two different lines but did not leave message on either.
still suspecting collections becoz we get so many of those.
(we pay our bills. being harassed by collections does not necessarily indicate one has reneged on an actual debt, sometimes it only means that some company has sold old accounts instead of closing them as requested. then the collectors resell to other collectors and it doesnt matter to them one bit that no money was ever past due in the first place.)

Sometimes those DC calls are from extortion scam outfits.  There's a major increase of those.

thanx, i agree.
sometimes when i google a number i will find out it's legitimate.  other times, google hits about a bazillion untrustworthy phone number listing sites and when a bunch of those appear to be from India, i figure the phone# is probly bad news.

one of those numbers i posted above turned out to be a new phone belonging to a relative.  the others i still have no idea & don't wish to engage since no msg was left.
one of them continues to call occasionally but never leaves a message.  that one just called on two different lines, one after the other, but did not leave message on either. they never do, so i am 95% certain it is no one i know.