Businesses have now declared open season on your ears -- even though the practice of pumping music and advertising into public airspace is apparently illegal.

At least three renovated midtown hotels -- The Row, The Novotel and the Midtown North Hampton Inn -- sport new speaker-laced awnings bleeding music into the street below, and an increasing number of stores and bars in midtown sport external speakers to blare music and acoustic attention grabbers into the ears of passersby.

Externally mounted flat screens adorn the edifices of theaters, sometimes with audio of performance outtakes or advertising. And in a growing trend, halal stands, sweet shops and souvenir outlets broadcast hip hop, rock and pop from boom boxes and externally mounted speakers.

While no data exists yet on the commercial creep, "we should jump in now and identify it," said environmental psychologist and CUNY professor emerita Arline Bronzaft. "If tourism has increased -- and apparently it has -- and merchants believe music attracts tourists to their shops, we should be alerted that the music will increase and make our streets even louder," said Bronzaft.

NYC Gifts owner Waleed Khan said he began broadcasting 92.3 NOW from speakers outside the store selling souvenirs late last year, after construction started nearby. His intention, he said, was to attract customers and pull people in from the east side of the street.

Pop music announces that "we're inviting and friendly," Khan said. "People don't always speak English, but people all over the world understand music," and no one has ever complained, he said.

The Novotel declined to comment on its public broadcasts, which an employee said was an Internet radio station. The Midtown North Hampton Inn and The Row did not respond to requests for comment lodged via corporate email.

But a spokesman for the City's Department of Environmental Protection, which is in charge of enforcing the city's noise code, said that "businesses may not broadcast music and/or promotional and commercial audio content, at any time, for advertising purposes."

New Yorkers kvetch plenty about clamor and commotion. 311 registered 6,694 complaints in 2013 from "noise from a store or business," although it's unclear what percent of those complaints involved noise leaking out of a restaurant, nightclub or bar versus those that are deliberately broadcast from a business. Another 15,434 "noise from street or sidewalk" complaints were received last year, although the majority of those are thought to be associated with construction.

The department issued 124 "notice of violations" for sound reproduction devices for sound or advertising purposes in 2013.

While the decibel levels of the latest audio assault may not be high enough to trigger hearing loss, the stress of unwanted audio stimulation still takes a toll on the human body, most markedly in the form of diminished cardiovascular health, said Bronzaft.

Adapting to unwanted sound "is always an added stress," and this "added intrusion makes the streets a little less comfortable," said Bronzaft, who would like to see more vigorous enforcement.

Residents complain periodically to Community Board 4 about hotel noise and especially about "Times Scare," the haunted house with ghoulish touts outside who are often armed with microphones, said Robert J. Benfatto Jr., district manager for Community Board 4. The Community Board asks the offending businesses to remedy the problem. "It quiets down for a while; then it starts up again," he said.

While the commercial appropriation of the air occurs in other U.S. cities, it is most pervasive in noisy NYC, said Eric Spangenberg, a marketing professor and dean of Washington State University's College of Business.

The practice "turns the entire city into an outdoor mall," said Spangenberg, who has studied the influence of music in retail environments. The creep of commerce into outdoor air often is associated with tourism, noted Spangenberg: People on vacation are more inclined to welcoming distractions than residents who are repeatedly subjected to sounds they don't select.

Businesses do it to "compete for people's senses and an emotional connection: They're creating a 360-degree experience that they hope people will encode," and associate with the brand, Spangenberg explained.

Yet, "I haven't seen any kind of research to show that this works," to lure customers or pump up profits, Spangenberg added. "It's become a 'me too!' kind of deal and it's assaultive," he said. "They're also driving certain customers away," and there are "serious social implications," to businesses feeling entitled to claim the attention of pedestrians in an already demanding environment, he said.

An informal poll of passersby found that various tourists described the music as "fun" or "a good thing," whereas residents were less enthusiastic.

Resident Kasey Callender, 33, noted she could hear the music broadcast by The Row Hotel "over my headphones," which she found "obnoxious."

Callender is a contract manager for a sound company, and wants it clear that "I adore music!" But "you shouldn't have to sell that hard," to people who haven't chosen to listen to it, she said.