Soundwave, the Decepticon communications officer and one of Megatron's staunchest supporters, doesn't just master the frequencies that carry information across our planet, he revels in them. Stationed high in the upper atmosphere and capable of processing millions of data streams at once, he is fully capable of taking over communications on a planetary scale. Whether he uses this to direct civilization or destroy it remains to be seen.
Soundwave has two extremely powerful weapons: his spread of sonic cannons... and Megatron. If any Decepticon crosses him, he does not hesitate to send a full record of said Decepticon's failures to Megatron, almost certainly ensuring an untimely demise. His lofty position has made Starscream suspicious, so Soundwave has his minion Ravage keep an eye on the Air Commander if he gets out of hand. Soundwave is also nearly defenseless in space, as his devastating sonic cannons only work within the atmosphere.
In Revenge of the Fallen, Soundwave spends his time hovering above Earth in orbit. He receives a message from Wheelie about Mikaela Banes possessing a shard of the Allspark and orders him to retrieve it. Docking onto a satellite and hacking it, Soundwave intercepts information on the location of Megatron's corpse and the Allspark shard. He deploy his servant Ravage to retrieve the shard and sent the Constructicons to rendezevous at Megatron's resting place. After the death of Optimus Prime, Soundwave carried out Megatron's orders to prepare the Decepticons for the invasion of Earth. While coordinating attacks, Soundwave located Sam Witwicky's parents in Paris, France, and called Judy Witwicky via her cell phone. He demanded she tell him where Sam was, but Judy did not take him seriously, believing him to be a pervert caller, and hung up. He later intercepted calls from the Egyptian government on Sam's location, and informed the other Decepticons. Soundwave did not take part in the last battle, although Ravage did and was killed by Bumblebee.
In Dark of the Moon, Soundwave is revealed to have been on Earth since the 1970s. He discovered the Autobot ship, the Ark on the Moon, and recruited various human servants from the U.S. and Russian space agencies to prevent further exploration of it following the initial Moon landings, while he ordered a large army of Decepticons to steal most of the pillars onboard and hide under the moon's surface. In the modern day he appears at Megatron's base in Africa, where he and Laserbeak report the Autobot's recovery of Sentinel Prime and the remaining pillars from the crashed Ark. Megatron praises Soundwave's initiative in the decades-long plan and orders him and Laserbeak to kill their human allies. The only human they don't kill, Dylan Gould, has Soundwave disguise himself as a Mercedes-Benz SLS AMG that belonged to Sam's girlfriend, Carly, in order to get close to the Autobots. He reveals himself and captures Carly once the two humans learn of Gould's alliance with the Decepticons, and threatens her in order to convince Sam to discover the Autobot's plans.
During the Battle in Chicago, Soundwave and Barricade lead several Decepticons in capturing some of the Autobots. Gould convinces Soundwave not to take prisoners, and Soundwave orders the others to execute their "trophies". Once Wheeljack is dead, Soundwave prepares to kill Bumblebee himself, but a Decepticon ship hijacked by Wheelie and Brains drops fighters near Soundwave, distracting him as the Autobots began fighting back. Bumblebee attacks Soundwave who tries to shoot him, but is confused among the crushing ships and shoots the other Decepticons. Bumblebee killed Soundwave by throwing an uppercut and sticking his gun in Soundwave's chest and shooting. This caused Soundwave's head to blast off, killing him instantly.
ALTERNATE MODES
Soundwave converts into a satellite that hovers above Earth. He is a Triple Changer, as he is able to transform into a Cybertronian jet as well.
In the third film, Soundwave disguises himself as a silver Mercedes-Benz SLS AMG. He has two sonic cannons that resembles a UZI.
