Interestingly, this shows how the current common thinking around memory is flawed. Memory is not like a muscle where brute forceing rote learning can help strengthen it. Instead, it's more like a set of processes. If you apply the right process, you can store stuff a lot easier.

The research method of linking visual to audio descriptions is very close to the loci method. This is essentially how folks create elaborate structures to "house" memories. The whole idea of a memory palace revolves around building a construct where you store vivid reminders, you then "walk" the palace now and then to reinforce the memory.

Linking is powerful, I have a cool trick you can try to demonstrate.

Write down a list of 10 to 20 words. It's easier to do this with nouns first. As you write each word, link it with the previous word in a vivid way. For example

Tree Dog Plane Flower

Picture a tree, which is being wee'd on by a dog, the tree then grabs and swallows the dog (tree - dog). Then picture a dog, a dalmation if you want standing, all relaxed on the street corner, when suddenly it starts transforming into a small spotted plane before flying off. (Dog - Plane). Next, you are on a plane, and you are all on your own. It's creepy when you look around. All you see are various flowers in the other seats.

Now, cover up the list, and you will find you can recall the full list. You can even do it in reverse..

The amazing thing is this can stretch to how many words you want. If you struggle on any part of the list, you will find this is because the image was not vivid enough. Make it absurd or disgusting if needed.

This system can be evolved and incorporated into things such as the loci system.

It has its weak points in its basic form as missing any link causes it to fail, but it illustrates how in seconds you can learn 30 words or more.

If you want a far better explanation, I would suggest reading Darren Brown's Tricks of the mind.