I know a caique that learned how to imitate a ringing telephone. They had to replace all the phones in the house with a different model, because they were constantly looking at dark caller ID panels that didn't ever say "your parrot".

Back when Facebook used a "pop" sound when you get a message, I was able to imitate it well enough to make my friends in the same room check their computer for messages!

In the late 90's early 00's, we had a pet cockatiel that could perfectly mimic the sound of dial-up modem dialing. He would also do the tunes to TV theme songs and a few regular TV ads.