murmur
mur-mur
noun
A soft, low, continuous sound, often indistinct or gentle.
"A soft murmur came from the crowd."
verb
To speak or say something in a soft, low, or indistinct voice.
"She murmured a quiet apology."
Thesaurus
Synonyms: heart murmur, cardiac murmur, murmuring, grumbling, mutter, grumble, muttering, murmuration, mussitation, croak, gnarl, murmur vowel