| indistinct(adjective, dull, hard, weak, soft) |
| faint(adjective, calm, dull, quiet, weak) |
| inaudible(adjective, dull, quiet, hard, weak) |
| gentle(adjective, calm, dull, weak, soft) |
| unclear(adjective, dull, quiet, weak, soft) |
| weak(adjective, dull, soft, gentle) |
| dim(adjective, dull, weak, soft, gentle) |
| dull(adjective, weak, soft, gentle) |
| pale(adjective, dull, weak, soft, gentle) |
| unhearable(adjective, quiet, soft) |
| muffled(adjective, dull, quiet, weak, soft) |
| muted(adjective, calm, dull, quiet, weak) |
| quiet(adjective, calm, dull, weak, smooth) |
| soft(adjective, calm, dull, quiet, weak) |
| distant(adjective, dull, weak, soft, gentle) |
| hushed(adjective, calm, dull, quiet, weak) |
| stifled(adjective, dull, weak, soft, gentle) |
| bated(adjective, dull, weak, soft, gentle) |
| whispered(adjective, dull, weak, soft, gentle) |
| closemouthed(quiet, soft) |