rustling vs susurrous

rustling is a noun but susurrous is not a noun.

Word	Noun	Adjective	Verb	Adverb
rustling	Yes	Yes	No	No
susurrous	No	Yes	No	No

As adjectives, rustling and susurrous are synonyms defined as:

Other synonyms of rustling include murmurous, soughing.

rustling (noun)	susurrous (noun)
the stealing of cattle
a light noise, like the noise of silk clothing or leaves blowing in the wind

rustling (adjective)	susurrous (adjective)
characterized by soft sounds	characterized by soft sounds