Hunting for a new home is hard enough without worrying about all the unpleasant surprises you may encounter after moving in – like finding out that your new bedroom is less than a mile from a jet engine testing facility. That fear of the unknown inspired Brendan Farrell to build a new online service called HowLoud to help Los Angeles residents scout out the average noise level in any neighborhood before they buy a new home.

Potential home-buyers can visit the free site and enter the address of any home in the L.A. area to retrieve a “Soundscore” of between 1 and 100 for that property. A home that scores 40 or below is said to have a "severe" noise level while a home that scores in the 90s is rated “peaceful.”

A three-bedroom home that is currently listed for $599,000 and located at 2203 S Cochran Ave., for example, returns a Soundscore of 65 because there are two auto repair stores nearby. An $899,000 three-bedroom condo in Brentwood is slightly quieter at 83.

The program calculates scores based on traffic patterns and the addresses of noisy places like schools, airports, railroads and 24-hour supermarkets. It even uses contour maps to measure how the slope of the land or a peculiar clump of buildings might shape the way sounds move toward a property. Farrell has submitted a patent application for the underlying technology, which is essentially a series of algorithms that takes all these factors into account.

Noise pollution is an important consideration for some buyers, and has been linked to health issues including stress, high blood pressure and loss of sleep, according to the EPA and the World Health Organization. Los Angeles, like many other cities, has set strict time periods for when garbage may be collected or construction may take place, but residents can further reduce their exposure by choosing quieter neighborhoods over loud ones. 

"There's a world out there that cares about noise,” Farrell says. And there is no standard way for real estate agents to disclose the amount of noise pollution that may plague a given property. “Noise is something that has not yet been dealt with the way so many other things have,” he adds.

Farrell, who has a background in applied and computational mathematics, says the data he uses is detailed enough that he could assign a separate Soundscore to the front and back yard of any property in the city. Though the service is free, Farrell wants to convince house hunters to pay for a custom sound report for a property, though he isn’t yet sure how much he would charge for one. He also wants multiple listing services, which host databases of for-sale properties in most major cities, to include a Soundscore in each listing. Though HowLoud is currently only available to L.A. residents, Farrell plans to launch a Kickstarter campaign in July to fund the nationwide roll-out of the program.

The program also works for commercial properties, so doctors, apartment developers or nursing home owners may also use it to find a quiet spot if peace and quiet is a priority for their business. Still, the system isn’t perfect. “Our roads in our model don't currently have traffic lights so traffic flows smoothly,” Farrell says. “We have to add traffic lights so there's that stop and start effect.”

Farrell was inspired to create the program while he and his wife bought a home in L.A. neighborhood Silver Lake. The Soundscore for his new property? A 58 -- he says he occasionally hears traffic and helicopters overhead but it’s not so loud that he can’t open the window in his office.