Technique of listening-in
lucid dreamingr listens inside his head, trying to hear if there is any noise or background static. If sound is heard, one must try to amplify it as much as possible through the same passive listening in.
Technique of forced listening-in
lucid dreamingr tries actively, and even strainingly, to hear sounds inside his head or background static with all his might. If this works, he tries to amplify those sounds as much as possible using the same active listening in.
Technique of imagining sounds
lucid dreamingr tries to hear some specific sound inside his head. Someone’s voice, familiar music, and the sound of one’s own name being called work best of all. If such sound arises, then the practitioner tries to make it as loud as possible.