Health and Human Services Secretary Robert F. Kennedy Jr. has attracted a lot of attention for his raspy voice, which results from a neurological voice disorder called spasmodic dysphonia^[1].

Kennedy, 71, says that in his 40s he developed a neurological disease that “robbed him of his strong speaking voice.” Kennedy first publicly spoke of the quiver he had noticed in his voice in a 2004 interview with journalist Diane...