MURMUROUS
murmurous, rustling, soughing, susurrous
(adjective) characterized by soft sounds; “a murmurous brook”; “a soughing wind in the pines”; “a slow sad susurrous rustle like the wind fingering the pines”- R.P.Warren
Source: WordNet® 3.1
Etymology
Adjective
murmurous (comparative more murmurous, superlative most murmurous)
Low, indistinct (of a sound); reminiscent of a murmur.
Source: Wiktionary
Mur"mur*ous, a. Etym: [Cf. L. murmuriosus, OF. murmuros.]
Definition: Attended with murmurs; exciting murmurs or complaint;
murmuring. [Archaic or Poetic]
The lime, a summer home of murmurous wings. Tennyson.
Source: Webster’s Unabridged Dictionary 1913 Edition