sonorousness vs plangency

sonorousness and plangency both are nouns.

Word	Noun	Adjective	Verb	Adverb
sonorousness	Yes	No	No	No
plangency	Yes	No	No	No

As nouns, sonorousness and plangency are synonyms defined as:

sonorousness and plangency: having the character of a loud deep sound; the quality of being resonant

Other synonyms of sonorousness include resonance, reverberance, ringing, sonority, vibrancy.

sonorousness (noun)	plangency (noun)
having the character of a loud deep sound; the quality of being resonant	having the character of a loud deep sound; the quality of being resonant