susurrant vs whispering

susurrant is not a noun while whispering is a noun.

Word	Noun	Adjective	Verb	Adverb
susurrant	No	Yes	No	No
whispering	Yes	Yes	No	No

As adjectives, susurrant and whispering are synonyms defined as:

Other synonyms of susurrant include murmuring.

susurrant (noun)	whispering (noun)
	speaking softly without vibration of the vocal cords
	a light noise, like the noise of silk clothing or leaves blowing in the wind

susurrant (adjective)	whispering (adjective)
making a low continuous indistinct sound	making a low continuous indistinct sound