Just when you thought there was nothing on this planet left to destroy, those gargantuan rock-'em sock-'em robots are back for Transformers: Age of Extinction.

And here comes the sonic boom. Because whatever else this crushing 3-D extravaganza is, it's certainly the loudest experience you will have this summer.

Age of Extinction should carry a new parental warning: May cause hearing damage.

Actually, director Michael Bay's fourth heavy-metal installment is sensory overload in every sense. Noise, action, rubble. Which wouldn't be so bad if it weren't so punishingly long - 2 hours and 45 minutes of furious pandemonium. You leave the cineplex feeling bludgeoned.

Ironically, in light of the havoc to come, the film has an almost lyrical start.

Mark Wahlberg has replaced Shia LaBeouf as the human protagonist. He's a crackpot inventor in a small Texas town, a widower who is understandably overprotective of his 17-year-old daughter (Nicola Peltz), seeing as how she wobbles around their dusty spread in 4-inch heels and Daisy Dukes.

Wahlberg unwittingly finds intergalactic robot hero Optimus Prime posing as a dilapidated truck in an old theater he's been hired to salvage. Left unexplained is why a semi is parked on the stage, and how it fit through the doors in the first place.

The autobots have become an endangered species, thanks to a shadowy CIA rogue (Kelsey Grammer) and his minion (Titus Welliver). Grammer's an excellent choice as a Transformers villain because his booming mechanical diction makes him sound like Megatron, Optimus' nemesis.

Other characters are bouncing around, such as Wahlberg's hang-loose helper (T.J. Miller) and a bobblehead billionaire (Stanley Tucci), both busily shoveling the movie's forced comic relief.

Then there's Peltz's boyfriend (Jack Reynor), one of those rare Texans with an Irish accent.

None of them matter after the first 20 minutes, when the robots assume command of the screen and take up their usual demolition mission.

To give Bay his due, Transformers is a testament to advances in CGI. The tableau of a giant alien spaceship hovering over Chicago, for instance, is breathtaking. Moments like that are quickly drowned out in the excessive uproar of this clanking cinematic claptrap. Go if you must, but bring earplugs.


Transformers: Age of Extinction ** (out of four stars)

Directed by Michael Bay. With Mark Wahlberg, Nicola Peltz, Jack Reynor, Kelsey Grammer, Stanley Tucci. In 3-D. Distributed by Paramount Pictures.
Running time: 2 hours, 45 mins.
Parent's guide: PG-13 (violence, profanity, adult themes).
Playing at: area theaters.