!Xóõ click perception by English, Isizulu, and Sesotho listeners

Many, though not all, nonnative phonological contrasts pose discrimination difficulties. The Perceptual Assimilation Model attributes discrimination differences to listeners’ assimilations of nonnative phones to their native phonologies, which vary across languages. We examined perception of two !Xoo click contrasts by American English speakers and speakers of Isizulu and Sesotho, African click languages that lack the target contrasts. The Africans should assimilate !Xoo clicks to native ones and discriminate accordingly; Americans should perceive them as nonspeech and discriminate them well. Isizulu’s click system is richer than Sesotho’s, so Isizulu speakers should perform better on at least one contrast. Americans should excel on contrasts that Africans assimilate to a single click. As predicted, Isizulu listeners assimilated !Xoo clicks to native clicks most often, Americans heard nonspeech most often. Sesotho listeners were poorest on one contrast they had difficulty categorizing. Americans excelled on the other, which the Africans assimilated to a single click.