| sing(verb, sound, agree, allow, acknowledge) |
| hum(verb, wait, shout, buzz, whistle) |
| purr(verb, wait, shout, whistle, chant) |
| vocalize(verb, state, express, put, wait) |
| drone(verb, buzz, recite, purr, whisper) |
| buzz(verb, wait, shout, whistle, purr) |
| warble(noun, verb, sound, wait, shout) |
| trill(noun, verb, wait, shout, tune) |
| carol(noun, verb, wait, shout, tune) |
| intone(verb, state, wait, utter, shout) |
| murmur(verb, whine, whisper, sing, mutter) |
| chirp(verb, sound, wait, shout, whistle) |
| chorus(noun, verb, shout, recite, song) |
| mutter(whisper, mumble, make a buzzing sound) |
| pipe(verb, wait, shout, whistle, chant) |
| chant(noun, verb, sound, wait, shout) |
| humming |
| yodel(verb, sound, wait, shout, whistle) |
| psalm(noun, repetition, tune, song, chant) |
| song(noun, repetition, tune, chant, cradlesong) |