Most if our cortex is devoted to vision, however
While I think it’s nonsense comparing what we do when we learn and what a computer
Program does, I’ll speculate on this.
Our eyes are doing a lot of signal processes before the “image” hits our brain. My understanding is audio has less signal processing required before the “sound” hits our brain.
(I know image generation models also use language, but to a much simpler extent, at least for now).