shrillness vs stridence

shrillness and stridence both are nouns.

Word	Noun	Adjective	Verb	Adverb
shrillness	Yes	No	No	No
stridence	Yes	No	No	No

As nouns, shrillness and stridence are synonyms defined as:

shrillness and stridence: having the timbre of a loud high-pitched sound

Other synonyms of shrillness include stridency.

shrillness (noun)	stridence (noun)
having the timbre of a loud high-pitched sound	having the timbre of a loud high-pitched sound
the quality of being sharp or harsh to the senses