Robert Kennedy Jr. talks "funny" because he has a neurological condition called spasmodic dysphonia. This condition causes spasms in the vocal cords, leading to a raspy, strained, and sometimes shaky voice. It affects the way his voice sounds, giving it a distinctive timbre and quiver that may seem unusual to listeners.

His voice is naturally gravelly and has a unique rhythm and intonation, which he uses effectively in his speeches to convey emotion and emphasize key points. The condition is not under his control and affects his ability to speak in a smooth, steady manner, which can result in the voice sounding "funny" or different from typical speech patterns.

In summary, the distinctive quality of Robert Kennedy Jr.'s voice is due to spasmodic dysphonia, a rare neurological disorder that impacts the vocal cords, causing a raspy and sometimes shaky speaking voice.