Mimi, a company launched Tuesday today as part of TechCrunch’s Disrupt NY Startup Battlefield, plans to use the iPhone to help people with hearing loss. I didn’t know much about the issue before discussing it with co-founders Philipp Skribanowitz and Pascal Werner, but they pointed me to a number of articles and studies about how widespread hearing loss has become, affecting an estimated 350 million people worldwide. And four out of five of those affected in the United States don’t seek treatment. The reason, Skribanowitz argued, is that the process of getting tested and fitted for hearing aids is long and complicated, and then the devices themselves are expensive (usually costing thousands of dollars for each ear). Mimi, on the other hand, is launching an iOS app that allows users to test their hearing using their existing earbuds.