Here is an excellent example of the McGurk effect:
My interpretation of this effect is based on the physics of both sound and light waves. Based on Shannon’s theorum, light carries more information than sound so it makes sense that our minds would, when presented with conflicting information. So it is understandable why many people operate on the principle of “seeing is believing”. However the McGurk effect should serve as a warning to us that when faced with problems of interpreting information, what we are seeing may be masking the truth of what we are perceiving.