The aksharas, alphabets, are very important for ShAktam. Each letter has a basic sound principle associated with it. The very creation is by the vibration of sound waves.
The elemental principle of ‘AkAsha’ produces, through vibration, subtle sounds, and from these sounds creation starts, from that the mantras, and the vedas that are full of mantras.
The subtle principle underlying AkAsha, that is, the tanmAtra associated with AkAsha, is ‘sound’.