About 12 percent of Americans suffer from some form of hearing loss, according to the Center for Hearing and Communication, an organization that offers hearing tests and speech therapy. And yet aiding those people is far more complicated than simply increasing the volume on a device, because no two people have the same kind of hearing loss, explains Barbara Kelly, deputy director of the Hearing Loss Association of America. “Every hearing loss has a different fingerprint,” she says.

A new smart-phone app called ACEHearing aims to address this via a simple test that diagnoses a user’s specific form of hearing loss and customizes the output of a mobile device to better match the listener’s ability to hear. Andrew van Hasselt, who chairs the ear, nose, and throat department at the Chinese University of Hong Kong, and who is one of the principal developers of ACEHearing, says the app is just a proof-of-concept prototype for a larger effort to add the functionality as a standard to phones and other devices that produce sound.

During the test, performed with headphones, the device plays sounds across a range of frequencies and asks whether the user can hear them. The software adjusts the device’s audio output by amplifying the most troublesome frequencies. This is important, because a smart-phone user who has trouble discerning speech because he can’t hear certain frequencies will gain nothing by simply turning up the volume.

Clinical trials have shown that the test that ACEHearing administers is equivalent to those administered by a traditional audiologist, says Paul Lee, director at Ximplar, a Hong Kong-based software company that worked with the Chinese University of Hong Kong to develop the app.

“It’s often five to seven years before a person who learns they have hearing loss addresses it,” says Kelly. The ACEHearing team hopes to circumvent this lag in treatment by providing an easy-to-use solution.

Brian Fligor, director of diagnostic audiology at Children’s Hospital Boston, is not convinced that ACEHearing will benefit those with hearing loss. He emphasizes the need for anyone with hearing loss to visit an audiologist and get a full exam. Fligor says, however, that the app could improve people’s audio experience more generally: “I can see benefit [in] anything that will improve someone’s music experience—I’m an audiophile.”

The ACEHearing team is in talks with several smart-phone manufacturers to incorporate their product into new phones.