What does the morsing do in a Carnatic concert?

The mridangam leads Carnatic percussion, and the morsing joins as an optional addition with the ghatam and kanjira. It shadows the mridangam through the concert, and players recite the mridangam's syllables silently and reproduce them with tongue and mouth. It also takes solo turns in the tani avartanam, and it reinforces the sruti and adds texture as well as rhythm.