The rf signals or radiofrequency or Hz of the purring cat - scientists try to replicate it in a purr box in a pillow - reminds me of the Emperor and the Nightingale, and how the expensive, ornate, man-made music box just could NOT REPLACE the plain little feathered bird singing outside his window....

A Chinese emperor prefers the tinkling of a bejeweled mechanical bird to the song of a real nightingale. When the Emperor is near death, a nightingale's song restores his health and teaches him to revolt against his glittering but shallow world.