Robert F. Kennedy Jr. has a rare neurological voice disorder called spasmodic dysphonia, which causes involuntary spasms in the muscles that control the vocal cords. This results in a strained, shaky, or raspy voice that can sound broken or strangled

. Kennedy first noticed symptoms in his 40s and publicly discussed the tremor in his voice in a 2004 interview

. Spasmodic dysphonia is a chronic condition believed to originate from abnormalities in the brain's neural networks, particularly areas like the basal ganglia and cerebral cortex that regulate muscle movement and coordination

. The exact cause remains unknown, and it affects about 50,000 people in North America, with women being more commonly affected than men

. Kennedy has undergone treatments including Botox injections to relax the vocal muscles, but he found this approach was not ideal for him due to sensitivity

. More recently, he sought surgical treatment in Japan involving a titanium implant to help keep his vocal cords from pressing together, which he credits with improving his voice

. In summary, RFK Jr.'s distinctive voice is the result of spasmodic dysphonia, a neurological disorder causing vocal cord muscle spasms that affect speech quality