What sound does a turkey's phone make?

The joke plays on the double meaning of the word “wing.” In one sense, “wing” is a part of the turkey’s anatomy, and in another, it sounds like the old-fashioned ring of a telephone. The punchline “Wing! Wing!” suggests that instead of a phone saying “Ring! Ring!” when it rings, a turkey’s phone would make a sound that references its own body part, thus “Wing! Wing!” It’s a simple play on words that creates a humorous mental image of a turkey having a phone and that phone making a turkey-appropriate noise.