Abstract
Language research over the past 40 years converges on the speech-is-special hypothesis (SiS), according to which speech perception and production are uniquely human adaptations. SiS is grounded in a variety of biological, developmental, and behavioral evidence. In some comparative studies, speechlike stimuli have seemed to cause nonhuman animals to exhibit humanlike performance functions. Auditorists—who believe that spoken language processing is executed by, and is explicable in terms of, general auditory mechanisms—have seized upon such studies as evidence that SiS is incorrect. However, it is difficult to identify biological and functional similarities across different species on the basis of behavior alone, and the elaborate training regimen that nonhuman animals require to achieve human performance levels undermines the significance of certain comparative studies. Both comparative and human behavioral research, including brain-imaging studies of functional localization, electrophysiological recordings of the neural basis of the perception-production link, and developmental studies of a time-locked schedule of language learning, favor SiS over auditorism.