A rare larnyx transplant has restored the voice of a California woman unable to speak on her own for more than a decade. Only one other successful larynx, or voice box, transplant has been documented, in 1998, say doctors who treated the woman at UC Davis Health System in Sacramento. They say the latest procedure, which included the transplant of a thyroid and trachea, was more ambitious. Before the October surgery, 52-year-old Brenda Charett Jensen could speak only through an electronic device that produced a robotic voice. Just 13 days later, the Modesto woman could speak on her own again. The voice is her own and not that of the organ donor. Her doctors say that is because its unique timbre resides in the palate, tongue, lips and sinuses, and the voice box simply vibrates to facilitate sound, akin to the reed on a clarinet.