When my voice mail picked up, the female voice seemed to be in the process of telling who it is and it's employer' name. The voice mail  said, "is being recorded."  The rest of the ten second message consisted of total science.

Didn't leave a message, hang up on recording

Didn't answer...
My phone message had a woman saying, "Hi, how are you ....."   click...
Probably, a collection office

Received hang up in voicemail.  Number blocked.

This #  calls everyday...I hear voices but no answer.  I think it is a computer or person trying to download info from my iphone.