I am interested in understanding the registers in Carnatic vocal music. I am aware of the concept of sthayis of Carnatic music but find myself in conflict when I try to relate it to the vocal registers (fry, modal, falsetto) as an SLP. Does sthayis in Carnatic music relate to the vocal registers commonly discussed in Western vocal pedagogy, such as chest voice, modal voice, and head voice?

Can you provide reliable references or sources on the registers of singing in Carnatic music? I am particularly interested in scholarly works or authoritative texts that delve into this aspect.