system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How can you hear yourself speak in your brain?

Most likely, while you are reading this you are narrating it in your head, unless you read everything out loud for some reason. Despite the fact there's not actually any sound waves, it's still possible to "hear" what you say. How does this happen?
gpt
The parts of your association cortex (that is, parts of the brain's neocortex that are not sensory processing areas) responsible for conscious thought and linguistic comprehension are working together to send signals back into your primary auditory cortex that you perceive as sound. Normally it is the other way around, with the auditory cortex sending processed sound signals to other parts of the brain. This is also how dreaming and imagining things works. When you are seeing and hearing and feeling things in a dream, information is actually flowing backward from the areas responsible for conscious thought, language, etc into your sensory processing areas.