susurrant

A man escaping from Biddle Island would do better to try his luck with the river, the tides, and the sharks, than to test the quiet susurrant heart of the marsh.

The atmosphere of the plane's interior was filled with the low murmur of a hundred conversations against the background of the susurrant mutter of the mighty engines.

Also, there lacked the persistent susurrant sound of the ventilation pumps.