| babble(noun, verb, low, utter, buzz) |
| burble(verb, whisper, mutter, mumble) |
| buzz(noun, verb, low, utter, babble) |
| drip(verb, utter, babble, whisper, mutter) |
| drone(noun, verb, low, utter, buzz) |
| flow(verb, utter, babble, whisper, mutter) |
| growl(verb, utter, babble, whisper, mutter) |
| gurgle(verb, whisper, mutter, mumble) |
| hum(noun, verb, low, utter, buzz) |
| make low(verb, expression, utter, babble, whisper) |
| meander(verb, utter, babble, whisper, mutter) |
| moan(verb, utter, babble, whisper, mutter) |
| mumble(noun, verb, low, utter, buzz) |
| mutter(noun, verb, low, utter, buzz) |
| purl(verb, whisper, mutter, mumble) |
| purr(noun, verb, low, utter, buzz) |
| ripple(verb, whisper, mutter, mumble) |
| rumble(noun, verb, low, utter, buzz) |
| stage-whisper(verb, utter, babble, whisper, mutter) |
| stammer(verb, utter, babble, whisper, mutter) |