Paul Frees was an American actor, composer, songwriter, voiceover artist and author who voiced the 'Ending Voiceover' of the 1970 film, Beneath the Planet of the Apes.
Either Paul Frees or William Conrad (depending on which source you believe) narrated the introduction to a March 1966 Planet of the Apes screen-test featuring Charlton Heston and Edward G. Robinson.