sound vs knocking

Other hyponyms of sound include bong, beat, beep, bleep, bell, toll, bombilation, bombination, buzz, chink, click, clink, chirp, chirrup, twitter, chorus, click-clack, clip-clop, clippety-clop, clop, clopping, clumping, clunking, cry, ding, drip, dripping, drum, footfall, footstep, step, gargle, gurgle, jangle, jingle, knock, murmur, murmuration, murmuring, mussitation, mutter, muttering, noise, drum roll, paradiddle, roll, pat, rap, tap, patter, peal, pealing, roll, rolling, ping, plunk, pop, popping, purr, quack, quaver, ring, ringing, tintinnabulation, drumbeat, rataplan, rub-a-dub, sigh, skirl, song, strum, susurration, susurrus, swish, tapping, throbbing, clump, clunk, thud, thump, thumping, thrum, thunk, tick, ticking, ting, tinkle, toot, tootle, trample, trampling, twang, vibrato, voice, vroom, whack, birr, whir, whirr, whirring, whistle, whistling, whiz, zing, zizz.