The Silent Parrot


A person enters a pet shop and sees a beautiful parrot. The seller guarantees him that the bird repeats everything it hears, so the person buys it. However, when he goes back home and tests the bird, it turns out that it doesn't say a word. The buyer goes to the shop to complain to the seller, but the seller argues he has not lied. How is this possible?

The parrot is deaf.