Celebrity-Endorsed Headphones Are the Rage at the Consumer Electronics Show The International Consumer Electronics Show in Las Vegas this week offered thousands of novel gadgets and high-tech products like remote-controlled indoor helicopters, ultrathin computer glass and refrigerators that play Pandora. It also generated a steady stream of news about what has become one of the most crowded product lines in music tech: expensive, celebrity-branded headphones, which according to some estimates have become a billion-dollar business. First, a prominent divorce. Beats Electronics, the company that pioneered the business, is ending its manufacturing deal with Monster Cable Products, Bloomberg Businessweek reported. Beats, founded by the hip-hop producer Dr. Dre and the music impresario Jimmy Iovine, has become the model for a branded electronics product, with retail prices up to $400 and constant promotion on "American Idol" by Mr. Iovine, a talent coach on the show. The company sold a majority stake last year to HTC, a Taiwanese cellphone and tablet maker, for $300 million. But can Beats maintain its sales momentum, with more competitors than Eminem had to face in "8 Mile"? In addition to lines already introduced by Quincy Jones, Ludacris and Jay-Z, there is Beats" old partner, Monster, which is also getting into the game. Monster's offering, as Businessweek notes, is a $200 pair of in-ear phones that "bears the name of the "70s soul act Earth, Wind and Fire." Next are the latest comers, which will be judged as much by their bass bombing as by the market value of the star who endorses or, in the case of the rapper 50 Cent, even makes them. At C.E.S., 50 Cent promoted his own line, which includes the $400 Sync by 50, which are wireless, and the $300 Street by 50, which have wires. Soon to come: Street by 50 earbuds, at $130. They are made by SMS Audio, a company that 50 Cent founded and runs. "I love music," he told The Los Angeles Times. Why would I not want to make the best possible way to hear it? Daddy Yankee, the Puerto Rican star of reggaeton, announced his own line, which sell for $150 and are made by Section 8. "I am constantly on tour and in the studio and headphones are an essential part of my day to day and while on the road," he said in a very prepared-sounding prepared statement, as reported by Billboard. Now we will bring fans and consumers a product that is my style and great quality. If any more proof of a product bubble were needed, look to Nicole (Snooki) Polizzi, the "Jersey Shore" player known more for public drunkenness than for discernment in audio technology. At C.E.S., she was swarmed by reporters as she endorsed the "bedazzled" iHip line. "It looks like me," she told MTV, holding a pair of silver glitter-covered headphones. Obviously I like to be tacky and I like to be gaudy.