Milton Selzer (born 1918) and Virginia Gregg (born 1916) play the parents of Alan Sues (born 1926) and Brooke Hayward (born 1937). Even more bizarrely, Sues (age 37 at time of filming) is described as a member of his school's football team.
When they have their masks on it's clearly visible they aren't really speaking, their vocal chords don't move.