Jasper, a 3-year-old short-legged terrier, gallantly defended the Henry household from a brief, high-pitched squeak Sunday night. According to safe and sound sources, the 18-pound canine launched from the living room couch upon hearing the peep and darted through the house multiple times in an effort to drive away the intruding sound. During his sweep of the premises, Jasper barked continuously and made brief stops in the kitchen, the living room, the bedroom, and the kitchen again, bravely putting himself between his family and the millisecond-long chirp. 'Easy, boy,' Tom Henry, 42, said. 'Easy.' As of press time, Jasper is standing at the ready in preparation for the squeak's return. 