The Collaborative International Dictionary of English v.0.48:

Hubbub \Hub"bub\, n. [Cf. Whoobub, Whoop, Hoop, v. i.]
   A loud noise of many confused voices; a tumult; uproar.
   --Milton.
   [1913 Webster]

         This hubbub of unmeaning words.          --Macaulay.
   [1913 Webster]

WordNet (r) 3.0 (2006):

hubbub
    n 1: loud confused noise from many sources [syn: hubbub,
         uproar, brouhaha, katzenjammer]

Moby Thesaurus II by Grady Ward, 1.0:

176 Moby Thesaurus words for "hubbub":
   Bedlam let loose, ado, agitation, apologetics, apologia, apology,
   argument, argumentation, babel, bedlam, bicker, bickering, blast,
   bluster, bobbery, boil, boiling, bother, botheration, brawl, broil,
   brouhaha, burst, bustle, cacophony, casuistry, chaos, charivari,
   chirm, churn, clamor, clangor, clap, clatter, commotion,
   contention, controversy, conturbation, defense, din, discomposure,
   discord, disorder, disputation, dispute, disquiet, disquietude,
   disturbance, donnybrook, donnybrook fair, drunken brawl, dustup,
   ebullition, embroilment, excitement, fanaticism, feery-fary,
   ferment, fermentation, fever, feverishness, fidgetiness, fidgets,
   fit, flap, flurry, fluster, flutter, flutteration, flutteriness,
   flyting, foment, fomentation, foofaraw, fracas, free-for-all,
   frenzy, fume, furor, furore, fury, fuss, fussiness, gaff, hassle,
   hell broke loose, helter-skelter, howl, hue and cry, hullabaloo,
   hurly-burly, inquietude, jangle, jitters, jumpiness, litigation,
   logomachy, loud noise, maelstrom, malaise, melee, moil, nerviness,
   nervosity, nervousness, noise, noise and shouting, outcry,
   pandemonium, paper war, passage of arms, passion, pell-mell,
   perturbation, polemic, polemics, pother, racket, rage, rampage,
   rattle, restlessness, rhubarb, riot, roar, roil, rough-and-tumble,
   roughhouse, rout, row, ruckus, ruction, rumble, rumpus, scramble,
   seethe, seething, set-to, shindy, shivaree, spasm, spurt, stew,
   stir, storminess, sweat, swirl, tempestuousness, thunder,
   thunderclap, tintamarre, to-do, trepidation, trepidity, trouble,
   tumult, tumultuation, tumultuousness, turbidity, turbulence,
   turmoil, twitter, unease, unquiet, unrest, uproar, upset,
   verbal engagement, vociferation, vortex, war of words, whirl,
   wildness, wrangling, zeal, zealousness