Robert F. Kennedy Jr. has spasmodic dysphonia, a voice disorder caused by a malfunction in the brain. Here’s what to know.

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,

Robert F. Kennedy Jr. will face the Senate for two days of confirmation hearings in a bid become the leader of Health and Human Services.

Kennedy's condition is called spasmodic dysphonia, which is a neurologic disorder that can affect the voice and speech by causing the muscles that generate a person’s voice to go into periods of spasm, according to Penn Medicine. It is a lifelong condition, but can be improved with treatment in some cases, according to Penn Medicine.

Spasmodic dysphonia is a rare neurological disorder that causes involuntary spasms in the vocal cords, making speech strained, breathy, or hoarse.

The sometimes difficult-to-understand speech of Robert F Kennedy Jr is not a stylistic choice but rather the result of a neurological condition known as spasmodic dysphonia. During his election campaign last year, Kennedy's raspy and gruff voice raised concerns among listeners, particularly when he spoke through microphones or on television.

Spasmodic dysphonia (SD), sometimes referred to as laryngeal dystonia, is a rare neurological condition impacting the voice and speech that impacts approximately 50,000 people in North America. For people with SD, muscles spasms in the larynx (also known as the voice box) cause the voice to sound tight, strangled or strained.

If confirmed by the Senate, Kennedy would head the Department of Health and Human Services (HHS), which oversees many of the country’s health agencies, from the Food and Drug Administration (FDA) to the Centers for Disease Control and Prevention (CDC).

Robert F. Kennedy, Jr., President Trump's nominee to serve as Secretary of Health and Human Services testifies during a Senate Committee on Health, Education, Labor and Pensions hearing for his pending confirmation on Capitol Hill,

The Senate Finance Committee will vote Tuesday on Robert F. Kennedy Jr's appointment to direct the U.S. Department of Health and Human Services.