These are Primordial Sounds . Primordial sounds were cognized thousands of years ago by Rishis, or Sages, and when they were recorded it was in relation to the moon. The moon has no particular significance in PSM, it just enables the reference point for recording the sounds. Mantras are sounds which take our awareness to quieter, more subtle levels. The word mantra means vehicle or instrument of the mind.
Any sound has an effect on our physiology.
Mantras are, therefore, a very important aspect of Primordial Sound Meditation. Mantras are used in all cultures and are used for a number of different purposes. The Mantras used in PSM are specifically designed as a vehicle to take our awareness 'in'. They have a very soothing effect on the physiology. During Primordial Sound Meditation our minds become quiet, allowing our bodies to gain the deep rest necessary to release stress and fatigue.