There's a distinct accent that American actors and broadcasters used in the early days of radio and in pre-World War II movies.

It's most obvious in old newsreel footage where the announcer speaks in a high-pitched tone, omits his “Rs" at the end of words, and sounds like a New Yorker who just returned from a summer holiday with the British royal family. This speaking style is also heard in the speeches of Franklin D. Roosevelt and just about any performance by Orson Welles.