| inconversable(adjective, close, quiet, soft, restrained) |
| indiscernible |
| inert(adjective, calm, quiet, smooth, tranquil) |
| inhibited(adjective, quiet, soft, still, silent) |
| inobtrusive(adjective, quiet, soft, gentle, low) |
| intimate(special, secret, private, personal, confidential) |
| laconic(adjective, quiet, soft, still, silent) |
| lenient(adjective, calm, dull, quiet, weak) |
| lifeless(adjective, calm, quiet, smooth, tranquil) |
| light(adjective, calm, dull, quiet, weak) |
| low-pitched(adjective, calm, dull, close, quiet) |
| masked(verb, concealed) |
| measured(adjective, calm, quiet, easy, mild) |
| mild(adjective, calm, dull, quiet, cool) |
| moldering |
| motionless(adjective, calm, quiet, cool, smooth) |
| murmuring(adjective, calm, dull, quiet, weak) |
| murmurous |
| neutral(adjective, quiet, cool, gentle, restrained) |
| nonpublic(special, intimate, personal, confidential, hush-hush) |