Alfred Hitchcock was in the Alfred Hitchcock business, which meant that he was eager to push his media image as the dry-humorous master of the macabre. He sold books, magazines, a television show and of course his films with this persona. It worked for him, but in later years he was disinclined to be serious in interviews. The great book that Francois Truffaut published of interviews with Hitch is terrific and insightful, but there aren't many really technical and specific interviews with him.
Here's a 20 minute segment of an interview that Hitchcock gave in 1966. He goes over some of his trademark laugh lines, but he also gives some pretty good technical details as well as a good insight into his philosophy of suspense.