A unique and defining trait of human behavior is our ability to communicate through speech. The fundamental organizational principles of the neural circuits within speech brain areas are largely unknown. In this talk, I will present new results from our research on the functional organization of the human higher-order auditory cortex, known as Wernicke?s area. I will focus on how neural populations in the superior temporal lobe encode acoustic-phonetic representations of speech, and also how they integrate influences of linguistic context to achieve perceptual robustness.