Dr. William F. House, 89, a medical researcher who braved skepticism to invent the cochlear implant, an electronic device considered to be the first to restore a human sense, died on Dec. 7 at his home in Aurora, Ore.

He pushed against conventional thinking throughout his career. Over the objections of some, he introduced the surgical microscope to ear surgery. Tackling a form of vertigo that doctors had believed was psychosomatic, he developed a surgical procedure that enabled the first American in space, Alan B. Shepard Jr., to travel to the moon.

Even after his ear-implant device had largely been supplanted by more sophisticated, and more expensive, devices, House advocated that it be used to help the world's poor.

Joan Mulhern, 51, a forceful advocate for the environment who lobbied Congress and often rallied public support to sway lawmakers to her cause, died Dec. 18 of liver disease at Georgetown University Hospital.

She had been the senior legislative counsel for Earthjustice, a nonprofit environmental law firm, since 1999. She fought repeated attempts by Congress to limit the scope of the Clean Water Act and battled coal companies and government officials over mountaintop-removal coal mining, in which mountains are blasted away to create strip mines.

In a regulatory world affected by changing politics, she found herself refighting battles that had seemingly been won decades before.