Nothing stops a crowd at Summerfest like a crowd at Summerfest.

Think about it; how many times have you seen traffic come to a halt on the grounds and stopped out of curiosity? It's usually a juggler, a guy on a unicycle, Bango Buck or another mascot, an arrest in progress or some other unusual event that causes the masses to stop and gawk.

Sometimes, you wonder if people at Summerfest will stand in any line at all, just to see if they'll get something free.

At about 3:30 Thursday afternoon, traffic stopped on the south end of the grounds. Dozens of people watched a presentation that featured 12 attractive young adults -- six male and six female -- in front of the Sennheiser Sound Tour display.

It looked a bit like an episode of a reality show, which was fitting because the participants in the Sennheiser Sound Tour are embarking on a 30-city journey that will see them undergo a series of challenges and star in "webisodes" that will be featured at sennheisersoundtour.com.

Sennheiser, a manufacturer of quality headphones and sound equipment, launched its program to create brand awareness among consumers with the unifying slogan "Hear. I Am."

The company is using its 12 "contestants" -- a group that includes musicians, actors, singers, a pro surfer and a pro gamer -- through a "Road Rules" meets "The Apprentice" meets "Stupid Human Tricks" set of tasks, most of which are designed to get passersby at festivals, concerts and sporting events to try on a pair of Sennheiser headphones.

"We've been coming up with ideas and things we can do to get headphones on people," said Scottie Hammond, a pro surfer on the men's team. "We want to integrate funny stuff, so people watching the webisodes will enjoy them."

The national launch was Thursday. In exchange for interacting with the launch Thursday afternoon, or promising to talk about the event on Facebook, Twitter and other social networking sites, some Summerfest patrons received a free pair of high-end earbud headphones.

"This concept harnesses the power of social media integrated with consumer activation. It provides the opportunity for listeners to actually 'discover, try and buy' Sennheiser headphones," said Anne Joyce, director of marketing for Sennheiser Canada.

"Sound lovers will soon discover the reason why Sennheiser has been the professional's choice in the audio and consumer electronics industries for decades."