Simplify the following text for a Grade 13 native English-speaking person.
Original: Avram Noam Chomsky ( ; born December 7 , 1928 ) , known as Noam Chomsky , is an American linguist , philosopher , cognitive scientist , and political activist .
Simplified: Avram Noam Chomsky ( born December 7 , 1928 ) is an American linguist , philosopher , political activist , author , and lecturer .