When something susurruses, it makes a soft, whispering sound, like leaves in the wind.
Susurruses are usually peaceful and calming, like the sound of a gentle breeze.
Examples:
The trees susurrus in the wind.
I love to listen to the susurrus of the stream.
The susurrus of the wind in the leaves is very calming.
The susurrus of the crowd was like the sound of the ocean.
The susurrus of the wind in the trees was like a lullaby.
The susurrus of the cat's purring was very soothing.