A systematic method (guided meditation) of inducing complete physical, mental and emotional relaxation;
performed - laying down; in the pose of shavasana making it suitable for just about all body types.
Yoga = Union or one pointed awareness
Nidra = Sleep
Nada = Sound / flow / river
Thus the concept of NadaNidra -
Is the conscious flow of sounds for the enhancement or use of guided awareness in yogic practice.