| rumble(noun, verb, sound, low, talk) |
| breathe(verb, tell, express, utter, buzz) |
| grouse(verb, criticize, protest, complain, grumble) |
| growl(verb, sound, criticize, low, protest) |
| grunt(noun, verb, sound, low, happy) |
| purr(noun, verb, sound, low, call) |
| whine(noun, verb, criticize, blow, protest) |
| wail(noun, verb, criticize, blow, protest) |
| grumbling |
| maunder |
| sough(noun, verb, cry, utter, flow) |
| susurrus(noun, sounds, vocalization, monotone, divulgence) |
| voice(noun, verb, expression, sound, low) |
| buzzing(noun, sound, low, buzz) |
| complain(verb, criticize, protest, cry, roar) |
| gnarl |
| gurgle(verb, sound, low, stir, protest) |
| lament(noun, verb, criticize, protest, cry) |
| ripple(verb, sound, low, stir, flow) |
| speak(verb, talk, utter, chatter, voice) |