Radio

A radio transmitter is a component of Transformer anatomy allowing them to communicate using radio, rather than sound.

Fiction

Generation 1 cartoon continuity

During their undercover operation to investigate a smuggling ring that was stealing airplane components, Slingshot found out his radio transmitter was removed and was, thus, unable to contact Silverbolt and the Autobots. Aerial Assault

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