susurrant vs murmuring

susurrant is not a noun while murmuring is a noun.

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

As adjectives, susurrant and murmuring are synonyms defined as:

Other synonyms of susurrant include whispering.

susurrant (noun)	murmuring (noun)
	a complaint uttered in a low and indistinct tone
	a low continuous indistinct sound; often accompanied by movement of the lips without the production of articulate speech

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