Or does it work something like this: you silently ask the Blessed Virgin Mary for her intercession, and she doesn't hear but God does, and then he tells her that you asked for her intercession, and she goes ahead and asks for that intercession?
Or does a silent prayer to a saint include automatic consent to him/her to get into your mind enough to hear that prayer?
One of those near-death-experience (Catholic) people, Gloria Polo, described seeing prayers as small flames as she floated above the earth; prayers from living saints, however, were like powerful flares, shooting much higher and brighter than the rest.