why is robert f kennedy's voice the way it is

Robert F. Kennedy Jr.'s distinctive voice is due to a rare neurological condition called spasmodic dysphonia. This disorder causes involuntary spasms in the muscles that control the vocal cords, leading to a strained, quivering, and sometimes halting voice. Kennedy first noticed symptoms in his early 40s, and the condition has affected his voice ever since. Spasmodic dysphonia disrupts normal vocal cord vibration, making speech sound shaky and tight but does not affect other vocal functions like laughing or crying. The cause of this condition is unknown, and it affects about 50,000 people in North America. Treatments include injections of botulinum toxin (Botox) to relax the vocal cords, though Kennedy found some treatments not suited to him. Despite the difficulty, Kennedy has said the more he uses his voice, the stronger it tends to get, although he remains dissatisfied with how it sounds.