NEW YORK -- Sometimes when Dirk Botterbusch is checking the weather online or listening to music on his computer, an ad starts talking or singing to him, pitching a new car or something else he doesn't need.
"It will scare me almost," he said. "I'd be on a site, just mousing over something and say, 'Where did that sound come from?"'
As a businessman himself -- he's a manager at Cingular Wireless in Atlanta -- Botterbusch sympathizes with the financial imperative of advertisers and Web sites. But he thinks the growing use of sound in online ads can backfire.
Advertisers know such tactics can annoy -- but they are also are mindful that the pitches work.
"If they weren't, we definitely would think about changing our tactics," said Mark Rattin, creative director of Otherwise Inc., whose Orbitz travel ads pervade the Internet. "People enjoy the surprises and interacting with them."
The first audio ads appeared perhaps three or four years ago, but only now have they become common enough for many users to notice. The "pop-under" ads from Orbitz all carry sound, Rattin said, while six months ago only half did.
Audio ads generally use Java, Flash, streaming or a combination of technologies and work on at least Internet Explorer on Windows computers, though many now are compatible with other browsers and Macintosh computers as well.
Credit -- or blame, depending on your viewpoint -- better technology, faster Internet connections and changes in advertising guidelines at Web sites for the increase in such ads.
Credit -- or blame -- the tendency for Web surfers to ignore ads without sound.
"One way to get someone to look at a banner ad when less than 1 percent look at them is to ping somebody with an audio cue," said Doug Stone, chief executive of ad agency Abstract Edge.
During the holidays, ads from Orbitz sang "hallelujah" as visitors moved their cursors over falling snowflakes. Another Orbitz ad featured a golf-putting game: Make the shot and hear applause from the crowd; miss, and get a sympathetic "oooo-ou."
The online ad agency itraffic created audible floating ads promoting shows on the Discovery Channel and sister cable networks. One pitching TLC's "Junkyard Wars" had sheets of metal flying over the Web page, with sounds of hammering and a bulldozer speeding by.
Other ads went beyond sound effects.
Ads for SBC Broadband had a narrative voice-over like television commercials. One for "Adaptation" had dialogue from the film and resembled a movie trailer.
Advertising agencies and Web sites say they've gotten smarter, so sound complements a message and heightens emotions rather than being a turnoff.
Audio "is more prevalent but in a more subtle fashion," said Jason Krebs, vice president of advertising for The New York Times' Web site. "It's not the audio for the sake of audio. Clients are smart enough to know that the annoyance factor plays more heavily."
Paul Iaffaldano, chief revenue officer at Weather.com, acknowledges that audio ads at his site were initially flops.
"Technically it went well, but from the consumer point of view, they did not like the fact that there was sound," he said. "Upon doing further research, we found that it's not that they minded sound, it was the sound that was picked."
Concerned about provoking user ire, many sites have developed policies to keep audio manageable.
Knight Ridder sites limit audio to 30 seconds within a 12-hour period, so the same ad would be silent the second time it runs. SportsLine.com generally requires a prominent "mute" or "close" button. At Microsoft's MSN, most sound must be user-initiated, which could involve someone simply passing over the ad with a cursor.
Despite the self-imposed constraints, not everybody's sold on audio. Its use remains relatively low -- only 5 percent of ads at the Times' site, for instance. And some sites still prohibit sound on ads.
"There's still a fear that it's intrusive, that their users will not appreciate it," said Blair Shapiro, itraffic's creative director.
Many users simply can't abide.
Georgia Kimmey, a former teacher and social worker in Houston, now keeps her speakers off.
"It's too annoying, too distracting," she said. "I would rather have it as an option, as a link as opposed to something that comes at you."
Ad-blocking software is another option but it kills the entire ad, not just the sound, and such programs sometimes inadvertently block useful, desired material as well.
For their part, advertisers aren't fazed about user backlash.
"People are going to begin to expect it," said Abstract Edge's Stone. "Five years from now, surfing the Internet and going to a Web site without sound will be analogous to watching television with the sound turned off."
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