What is "leave with pre-trained" in learning to listening context?

Question

Paragraph taken from The Key to Learning Pronunciation, written by Fluent Forever. It discusses about a method to improve the ability of listening for language learners: learning with feedback. The limit of this method is 80% accuracy.

What if we had this tool in every language? What if we could start out by taking a few audio tests with feedback and leave with pre-trained, 80% accuracy ears, even before we began to learn the rest of our language?

If the ears are trained from 50% accuracy to 80% accuracy, why is it called pre-trained? And since we use those ears to learn the rest of the language, why does the author use leave?

Answer 1

Think of the order of actions this way. Basically leave indicates moving on to the next action. So:

First:

taking a few audio tests with feedback (the training)

Second:

leave (from wherever you went 'theoretically' for those tests) with 80% accuracy ears

Third:

began to learn the rest of our language (with the 80% accuracy ears we now have). It is pre-trained because we got this ability in the first step above.

To understand leave better, you could replace "a few audio tests with feedback" with "a training class" (in a classroom environment).

What if we could start out by taking a training class, and leave (the class) with pre-trained, 80% accuracy ears...

The definition used for leave would be:

8) to go away from ⇒ "to leave the house"