America's hearing-impaired are hailing Monday's unveiling of the 'Sentinel 450,' a breakthrough alarm clock that awakens deaf sleepers without the use of hammers. The alarm clock, developed by Metuchen-based Integrated Products, uses a flashing strobe light to wake hearing-impaired sleepers, rendering obsolete previous models utilizing a mechanical arm to pound the sleeper's cranium with a ball-peen hammer. 'Rise and shine in an delightfully new, painless way,' trumpets the brochure for the Sentinel 450, expected to hit store shelves in early January. 'Now you can be on time for work without all the debilitating concussions, cranial fractures and costly reconstructive facial surgery.' 