Voice Box

Have you ever heard a strange robotic voice, then turned to see someone speaking through an electrolarynx? For victims of laryngeal cancer, a buzzer pressed to the neck restores speech by stepping in for lost vocal cords, but produces machine-like sounds that can be hard to understand.

In an effort to restore natural pitch and control, Massachusetts Eye and Ear Infirmary researchers are developing an electrolarynx commanded by the same nerve signals that normally control the voice. The strategy is to attach laryngeal nerves to small muscles in the neck, then use electrical signals from those muscles to turn the electrolarynx on and off and control its frequency. Doctors have re-routed nerves in nine patients so far. Project leader Robert Hillman says neural control would allow hands-free operation of the electrolarynx. Eventually, the entire system could be implanted.