The Collaborative International Dictionary of English v.0.48:

Raucous \Rau"cous\ (r[add]"k[u^]s), a. [L. raucus.]
   Hoarse; harsh; rough; as, a raucous, thick tone. "His voice
   slightly raucous." --Aytoun. -- Rau"cous*ly, adv.
   [1913 Webster]

WordNet (r) 3.0 (2006):

raucous
    adj 1: unpleasantly loud and harsh [syn: raucous, strident]
    2: disturbing the public peace; loud and rough; "a raucous
       party"; "rowdy teenagers" [syn: raucous, rowdy]

Moby Thesaurus II by Grady Ward, 1.0:

78 Moby Thesaurus words for "raucous":
   absonant, atonal, boisterous, brassy, brazen, brusque, cacophonous,
   choked, coarse, cracked, croaking, croaky, diaphonic, disconsonant,
   discordant, disharmonic, disharmonious, disorderly, dissonant, dry,
   ear-splitting, flat, grating, gruff, guttural, harsh,
   harsh-sounding, hoarse, husky, immelodious, inharmonic,
   inharmonious, jarring, loud, metallic, musicless, noisy,
   nonmelodious, off, off-key, off-tone, out of pitch, out of tone,
   out of tune, piercing, ragged, rasping, raucid, rough, roupy,
   rowdy, rowdyish, rude, rumbustious, scratching, scratchy, sharp,
   shrill, sour, squawking, squawky, stertorous, strangled, strident,
   stridulous, termagant, thick, throaty, tinny, tumultuous, tuneless,
   unharmonious, unmelodious, unmusical, unruly, untunable, untuned,
   untuneful