But I'm a visual/textual learner. I need to see words written down.

This belief stems from the misconception that there are different kinds of learners. This is called the “learning styles hypothesis”, which, besides having no evidence for its existence, has been disproven: The truth is that the senses that we use to learn each ability depend on the ability we are learning, not on the person learning it. You can’t learn to drive a car by reading, or learn to paint by listening. When people identify themselves as “visual learners” or “verbal learners“, it’s not because they can learn a new language better or faster by looking at written words than by listening to them. The reason is that they’ve found that it’s easier to remember the spelling of a written word in a known alphabet than to remember the sound of a word after hearing it being spoken in an unknown language. But the reason why that happens is not that they generally learn better by looking at things than by listening. The real reason is that the sounds of the new language don’t yet exist as concepts in the brain of a new learner, while the letters of the Roman alphabet already have their own place in their brain. It is easier for their brain to form connections between concepts that already exist than to create entirely new concepts for the new sounds. But concepts for the sound system of the new language need to be created, or your brain will use the ones that of your first language instead. Luckily, once you listen a lot and learn the sounds of the new language well, you'll have an equally easy time remembering new words when you hear them, and you won't be influenced by the sounds of your native language. To learn more about this, check out our blog post The mythical visual learner.