New Delhi, Feb. 3 -- American politician Robert F. Kennedy Jr. once had a very strong voice. But last month when he appeared during the Senate confirmation hearing for his nomination to the US Secretary of Health and Human Services, the tremble in his voice was hard to miss. The 71-year-old has been vocal about suffering from spasmodic dysphonia, which has impacted his voice since he was in his 40s. It is a rare neurological disorder that affects the muscles in the voice box. People with this disorder may have a shaky voice or not be able to speak at all. There is no cure for it, but there are treatment options to manage the symptoms.

Robert F. Kennedy Jr. on his voice

Even though many people pointed out the change in the voice of Rober...