Kennedy's condition is called spasmodic dysphonia, which is a neurologic disorder that can affect the voice and speech by causing the muscles that generate a person’s voice to go into periods of spasm, according to Penn Medicine. It is a lifelong condition, but can be improved with treatment in some cases, according to Penn Medicine.

Spasmodic dysphonia is a rare neurological disorder that causes involuntary spasms in the vocal cords, making speech strained, breathy, or hoarse.