Six years of working at a nonprofit offering rental housing to low-income families taught John Bialk just how precious quiet can be. He frequently fielded noise complaints from tenants—from late-night parties to loud TVs. And these issues often led to nasty feuds between neighbors. “I’d see cars keyed, tires flattened, physical threats,” says the Neshkoro, Wis., resident. “As a property manager, you sit at your desk waiting for bad things to happen.” In the meantime, he came up with a solution: a noise-monitoring system that works on a wireless network to alert landlords to problems.

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