Oral circuits

A Transformer's oral circuits are related to vocalization.

Fiction

Marvel UK

The Magnificent Six! Prowl cleared his oral circuits to cover up his daydreaming during one of Optimus Prime's boring lectures.

Transformers (2007)

Bumblebee had his oral circuits damaged in a battle with the Decepticons, redering him unable to communicate with other species, though still able to communicate over inter-Autobot frequencies. Ratchet had been having trouble fixing them ever since. Transformers

From Teletraan I: The Transformers Wiki, a Wikia wiki.