Soundwave was one of the Decepticons in Transformers; in other words a bad guy. He could transform into a cassette player that could record the secret plans of the Autobots or transmit messages back to Cybertron. He has the ability to hear faint noises and a limited ability to read minds. He is distinguished from the other Decepticons by his distorted voice with blue, white and yellow as his colours. He could also eject cassette tapes that could transform into smaller robots (also know as the Cassetticons). These smaller robots helped him render various tasks such as espionage, defense or offense against both Autobots and Decepticons.

Among the Cassetticons were:

Squawktalk and Beastbox could combine to form a bigger robot called Squawkbox.

In the French version of Transformers, Soundwave is known as Radar.