| secretive(adjective, close, quiet, soft) |
| speechless(adjective, close, quiet, soft, obscure) |
| taciturn(adjective, close, quiet, soft) |
| tight-lipped(adjective, close, quiet, soft) |
| uncommunicative(adjective, close, quiet, soft) |
| unexpressed(adjective, close, quiet, soft) |
| unspeaking(adjective, close, quiet, soft) |
| unuttered(adjective, close, quiet, soft) |
| voiceless(quiet, soft, silent) |
| whispered(adjective, dull, quiet, weak, soft) |
| whist(adjective, close, quiet, soft) |
| wordless(quiet, soft, silent, voiceless) |
| closemouthed(quiet, soft) |
| discreet(adjective, soft, silent, understated) |
| nonvocal(quiet, soft) |
| not talkative(expression, quiet, soft) |
| out of earshot(expression, idiom, quiet, weak, soft) |
| reedy(adjective, dull, soft, dim) |
| tasteful(quiet, soft) |
| unaccented(adjective, dull, soft, dim) |