1.  susurration(n = noun.event) susurrus - the indistinct sound of people whispering; "a soft susurrus of conversation"
is a kind of sound
Derived form verb susurrate₁

2.  susurration(n = noun.communication) voicelessness, whisper, whispering - speaking softly without vibration of the vocal cords;
is a kind of speaking, speech production
has particulars: stage whisper
Derived form verb susurrate₁

   A whispering; a soft murmur. Howell. [1913 Webster]

susurration, n. (also susurrus) literary a sound of whispering or rustling.

Etymology:
ME f. LL susurratio f. L susurrare

N  faintness, faint sound, whisper, breath, undertone, underbreath, murmur, hum, susurration, tinkle, still small voice, hoarseness, raucity, inaudible, scarcely audible, just audible, low, dull, stifled, muffled, hoarse, husky, gentle, soft, faint, floating, purling, flowing, whispered, liquid, soothing, dulcet, susurrant, susurrous, in a whisper, with bated breath, sotto voce, between the teeth, aside, piano, pianissimo, d la sourdine, out of earshot inaudibly, (ii) SPECIFIC SOUNDS.