Watch This - Corvid Noises
Fable the Raven is a captive bred bird that lives with a Falconer in the UK. In this video you can hear the many noises she can make, and her handler talks about how she teaches Fable new words to mimic. (It's also handy to watch this video about Fable too, it helps explain that she is not a pet or a wild bird, and it should ne noted that keeping Corvids is illegal in the US without special Federal permits.)
Craft Idea - Bird Whistles
You can whistle like a bird with your own homemade bird whistle. Please note - This craft is only appropriate for older children and adults, as it does go in the mouth and can pose a choking hazard.
Activity Idea - Bird Song Hero
Cornell's Lab of Ornithology has a fun interactive game that uses visuals of bird songs to teach what they sound like. Give it a try, maybe you'll be a Bird Song Hero!
Watch This - Why Parrots Can Talk
This video from VOX, does a great job explaining a bird's syrinx and how it works to help parrots and other birds 'speak'. There is also this video that shows how the birds internal stuctures move when they are producing sound.
External Links to Check Out -
10 Common Bird Songs Made Less Confusing article from Audubon