Clairaudience is the ability to hear things intuitively. You might experience song lyrics that just pop into your head. Pay attention to the words of these songs because they can be messages from your spirit guides and loved ones on the other side.
Your inner, clairaudient voice will sound like your own voice. But remember, when our ego talks to us, the messages are fear based and urgent. When our intuition talks to us, the messages are consistent, loving and gently repetitive.
Some great crystals for this ability include Blue Lace Agate, Sodalite and Blue Chalcedony. Great yoga poses to increase Clairaudience include Fish Pose and the Plough.