THESAURUS
murmuring
aspiration, bated breath, beef, beefing, bellyache, bellyaching, bitch, bitching, breath, breathy voice, complaining, complaint, complaintful, crabbing, crabby, cranky, croaking, destructive criticism, disappointed, discontented, disgruntled, displeased, dissatisfied, dissent, drone, droning, envious, exhalation, faultfinding, gabble, gibber, gibbering, grievance, gripe, griping, groan, groaning, grouchy, grouse, grousing, growling, grumbling, holler, howl, jabber, jibber, kick, kicking, little voice, low voice, malcontent, malcontented, maundering, mouthing, mumble, mumbling, murmur, murmuration, murmurish, murmurous, mutter, muttering, out of humor, peeve, peevish, peevishness, pet peeve, petulance, petulant, protest, querulant, querulous, querulousness, rebellious, resentful, restive, restless, rustling, scolding, sigh, sniping, soft voice, squawk, squawking, stage whisper, still small voice, sulky, susurrant, susurration, susurrous, susurrus, unaccepting, unaccommodating, underbreath, undertone, uneasy, unfulfilled, ungratified, unhappy, unsatisfied, whining, whiny, whisper, whispering, whispery, yapping