Synonyms for Guttural (same or very similar meaning)
WordNet sense 1 (a consonant articulated in the back of the mouth or throat):
pharyngeal, guttural consonant, pharyngeal consonantWordNet sense 2 (like the sounds of frogs and crows):
croaky, croakingWordNet sense 3 (having an unpleasant sound):
cacophonous, cacophonicFrom the ODE community, based on WordNetadd/edit