Ku-khru-kru

Chaucer to Shakespeare up-to romanticism, None of the writer define this Sound, organism! Origin of THY sound, obscure and  Unfold, Even from dictionaries, Cambridge and Oxford! May be wise that of romanticists, Wordsworth and Coleridge, They all seems to fail, before THOU made rhyme! Even I got shocked! When heard  "ku-khru-kru" Invisible, Delphic, superb, word of thou! Only word, fluctuated sound, find very rare, But whose delineation, not easy to share! May be! THY built, any bird encyclopedia, Human could be answer, to "ku-khru-kru" chidia...