Now that we have seen the hardware for hearing, the next part is to understand how we perceive sound. In the visual case, we saw that perceptual experiences are often surprising because they are based on adaptation, missing data, assumptions filled in by neural structures, and many other factors. The same is true for auditory experiences. Furthermore, auditory illusions exist in the same way as optical illusions. The McGurk effect from Section 6.4 was an example that used vision to induce incorrect auditory perception.