Susurration.
I always enjoy encountering a word that I’ve never read or heard before.
Susurration.
Lexico.com provides this meaning:
Whispering or rustling.
‘the susurration of the river’
‘It settled to the ground with a soft susurration like stirring leaves.’
‘Something beautiful but so far away-like the music of a faraway violin or the susurration of a distant wave.’
Origin
Late Middle English from late Latin susurratio(n-), from Latin susurrare ‘to murmur, hum’, from susurrus ‘whisper’.
mgpcpastor's blog 
Great word, yes. Have you read Terry Pratchett? https://www.theguardian.com/childrens-books-site/2016/jul/05/the-shepherds-crown-terry-pratchett-review
I haven’t read much Pratchett, which is another oversight that will blow my kid’s minds. They have read him, so I don’t feel like a complete failure.