The antonyms for the word "more sounding" are "less resonant," "quieter," "unimpressive," and "inaudible." While "more sounding" refers to something that produces a clear or loud sound, its antonyms are the opposite - they refer to sounds that are barely audible or not noticeable. For example, a whisper is less resonant than a shout, and a faint murmur is quieter than a blaring horn. In some cases, the context may dictate which antonym to use. For instance, "unimpressive" may be more appropriate when describing a lackluster speech, while "inaudible" may be more applicable to a muffled radio transmission.