Synonyms for Murmur:

n.

beat, gurgle, drip, noise, aorta, burble, B, peal, bleeding, anticoagulant, meander, atrium, ripple, atheroma, artery, tinkle, abo system, hum, trickle, ooze. fizzle, peep, pitter-patter, breathe, pad, pit-a-pat. protest, rant, complaint, sigh, susurrus, sough, susurration, remonstrance. happy, grunt, raise the roof, take something further, kick up a fuss/stink/argument, lodge, complain. under your breath, purr, croon, hiss. ramblings, stage whisper, patter, ramble. pulsate, resonate, roar, buzz, resound. event (noun)
murmuring, mussitation, muttering, murmuration, mutter.
low, continuous sound (noun)
purr, buzz, whisper, mutter, grumble, susurration, murmuration, hum, muttering.
murmur (noun)
murmur vowel, muttering, croak, cardiac murmur, gnarl, grumbling, murmuration, murmuring, mussitation, mutter, grumble, heart murmur.
voice (noun)
emission, enunciation, articulation, intonation, utterance, pronunciation, speech, exclamation.

v.

make low, continuous sound (verb)
meander, trickle, utter, ripple, voice, moan, gurgle, drip, burble, tinkle.
voice (verb)
exclaim, emit, intone, articulate, mutter, enunciate, moan, voice, pronounce, utter, cry, whisper, speak, groan.

Other synonyms:

pitter-patter, pit-a-pat, resound, ramblings, stage whisper, remonstrance, croon. pulsate, peep, resonate, sough, sigh, rant, fizzle. burble, protest, ramble, breathe, patter, purr. ripple. hiss. lodge, pad. buzz. buzz
hum.
ripple
gurgle.
Other relevant words:
resound, resonate, beat, peep, pulsate, drip, susurrus, murmuration, hum, grumbling, B, atrium, complaint, aorta, murmuring, hiss, pit-a-pat, pitter-patter, noise, meander, croak, sigh, purr, patter, anticoagulant, mussitation, rant, gnarl, complain, peal, artery, sough, happy, lodge, ramble, bleeding, protest, trickle, grunt, ooze, ramblings, atheroma, muttering, remonstrance, fizzle, susurration, cardiac murmur, pad, gurgle, heart murmur, murmur vowel, breathe, tinkle, buzz, burble, croon, grumble, ripple, roar.

Usage examples for murmur

  1. When she came home to dinner the sitting- room door was still closed and a steady murmur of voices could be heard. – Chicken Little Jane by Lily Munsell Ritchie
  2. There was a murmur as if someone were singing, far away. – Raggedy Ann Stories by Johnny Gruelle
  3. Then, I seemed to hear a distant murmur a faint sound of voices. – Atlantida by Pierre Benoit