Major hypotheses tested in this experiment were that (a) auditory discrimination ability is influenced by the native language background of the listener and (b) auditory discrimination ability increases with maturation. The subjects were 142 English-speaking and 84 Spanish-speaking children distributed throughout the 1st, 3rd, 5th, and 7th grades. The dependent measure was a test of auditory discrimination ability consisting of taped pairs of nonsense utterances. Members of each pair were either identical or distinguishable from each other by a single sound. Analysis of variance by grade, sex, and language background was applied to the results. On the total test and on Section 1 (neutral items), there was significant variation due to grade, but not to sex or language background (all significance levels were p<.01). Analysis of Section 2 (English-based items) and Section 3 (Spanish-based items) showed significant variation due to grade and language background. The English-speaking children performed better than Spanish-speaking counterparts on Section 2. The reverse was true on Section 3. Results suggest that any discussion of auditory discrimination ability which does not take into account the native language background of the listener is likely to overlook a highly significant variable and lead to tenuous conclusions. (Author/LS)