the world > physical sensation > hearing and noise > degree, kind, or quality of sound > faintness or weakness > [noun] > faint or weak sound > murmuring sound
murmuringc1385
murmur?a1425
murmell1535
babblea1592
muttering1613
huma1616
mussitation1649
simmering1689
croon1725
babbling1736
brool1837
brooling1837
brum1842
babblement1860
1837 T. CarlyleFrench Revol. II. iv. iv. 229 The People also is calm;..With but a few broolings.