They will hear you if you speak to them telepathically in your head. I used to wonder the same thing. Great question.
What you want to do is try to form a connection so that when you do need to get a message to or from them it's a little easier to tune in. It's like shouting into the wind if you're not very good at connecting with them. But if you are practiced at it and know your guides, it's like having a crystal clear phone connection ( or a Bat phone with an instant, single, dedicated connection).
