Symran from the Sanskrit word Smriti means to “remembering” although it’s normally translate as “mindfulness” and in this context it is remembering to be here in the Present moment, as opposed to “being” in our normal fantasies of the future or replaying something from the past.
Symran is concerned with the immediate reality, unlike science, which is concerned with knowing immediate objective reality; the use of sound in meditation is to know one immediate subjective reality.
One can only listen to sound in the present moment, anything else is just impossible, however, there are obstacles in accessing this immediate reality of sound with clear present moment awareness, such as, our normal conditioning of listen to the internal dialogue which is going on within our minds, as opposed to listening with clear awareness.
The powerful physical and psychological impact of Symran has been demonstrated in the West through techniques such as Transcendental meditation or Primordial Sound Meditation.
Sound
According to Wisdom tradition and practical experience, define sound as that which conveys the idea of an object, indicates the presence of a speaker and constitutes the subtle form that conveys quality of the sound produced, e.g. something said in anger or love, may convey the quality of origination of sound produced.
Mantra is a special sound which is considered to contain an inherent beneficial quality realised through its vibrations. “Man” mean the mind, and “Tra” means technique. Therefore Mantra is a sound that enables us to realise our true Self.