crows and ravens have vocal cords and can reproduce sounds, even human sounds
its why Ravens are protected in many places, due to , many feel they have spirits in them

I was once on a hunt up in Alberta Canada, and one landed in a tree near me and kept says, HELLO, HELLO!
I thought I was loosing my mind, then talked to the outfitter and he told that raven was known in the area by all the locals and other hunters

on a side note, I knew a older guy, he had a crow as a pet bird and it said all sorts of things!

he also used to have pet skunks, and just had there scent glands or what ever removed
he told me they made great pets and, worked super well at keeping crooks away! LOL