(NewsNation) — Democratic presidential candidate Robert Kennedy Jr. explained Wednesday how he came to have a raspy voice, noting a neurological disease in his 40s.

Kennedy said he suffers from a condition called spasmodic dysphonia, which causes the muscles that generate a person’s voice to go into periods of spasm.

“I think it makes it problematical for people to listen to me. I cannot listen to myself on TV. … I feel sorry for you guys having to listen to me,” Kennedy said.

During a town hall at the NewsNation headquarters Wednesday, Kennedy answered questions from voters, as well as voters voters watching in South Carolina and New Hampshire.