Overall, the investigators hypothesize that the groups tested will differ in their neural indices of auditory perception, neural indices of perceptual organization, and induced neural oscillations. Further, the investigators hypothesize that differences in the degree of language impairment across these groups will be correlated with differences in the degree of abnormality of the measured neural indices, but not in the form of the abnormality, suggesting that the root causes of the differences across the tested subject groups are quantitative rather than qualitative.