Noun

• S: (n) rustle, rustling, whisper, whispering (a light noise, like the noise of silk clothing or leaves blowing in the wind)
• S: (n) whisper, whispering, susurration, voicelessness (speaking softly without vibration of the vocal cords)

Verb

• S: (v) whisper (speak softly; in a low voice)

Adjective

• S: (adj) murmuring, susurrant, whispering (making a low continuous indistinct sound) "like murmuring waves"; "susurrant voices"