Robert F. Kennedy Jr. (RFK Jr.) speaks the way he does primarily because of a neurological condition called spasmodic dysphonia. This condition causes involuntary spasms in the muscles of the larynx (voice box) that affect vocal cords, leading to a distinctive raspy, broken, and sometimes strained or breathy voice quality. It is a rare disorder affecting about 50,000 people in North America and impacts the coordination of muscles controlling vocal sound, resulting in the characteristic breaks and roughness in his speech.

In addition to the physical effects of spasmodic dysphonia, RFK Jr.'s speaking style is also marked by deliberate pacing, strategic pauses, and varied intonation. These speech patterns emphasize key points, convey emotional depth, and create a thoughtful, engaging delivery. His vocal timbre, which has a gravelly texture, adds authenticity and gravitas, making his speeches impactful and compelling.

Thus, his unique voice and speaking manner arise both from the neurological condition and his intentional rhetoric techniques used to communicate effectively with audiences.