The caller does not leave a message, but will wait for the prompt to leave one. Irritating

This phone call was suspiciously odd. . it seemed like when I answered and said: Hello this is Em; it recorded
what I said .... then I heard a beep right after I said: Hello this is Em; as if it just recorded my greeting; after the beep it said in a robot recorded voice: 'thank you, goodbye'.  I heard that there are companies that are trying to get voice matches to phone numbers and people. . . is this true? , I dont know, but this type of call makes me super suspicious, so much so that I am going to try to find out how to block this number. ~Em

is that a company calling?

Who is this and why are you calling me and hanging up after I answer

I have received a call from this "number" twice and they both have come of District of Columbia , yea right.. Call it back and it is a non working number.. So again, scammer are at it !!!! It is no annoying !!!