The Waterton area actually tested three different types of electronic voting kiosk, each of which utilizes a number of different methods (e.g. touchscreen, audio announce, sip/puff controls) to ensure the greatest number of disabled Americans have complete control over the voting process.
Voting machines designed to accommodate the needs of blind and other disabled voters were tested in Watertown, Waltham, and Woburn, part of an effort to find a system that will be used statewide as Massachusetts tries to comply with federal legislation mandating equal treatment for voters with disabilities.
The 2002 Help America Vote Act requires all states and jurisdictions to have accessible equipment by Jan. 1, 2006.
The full article is here.