[immutology]

From what I've read, the Koch method combined with Farnsworth timing is the best way to learn to hear Morse code.

Koch method is about using full-speed dits/dahs from the beginning and gradually adding a couple to the set of characters being trained as you learn to identify them by their sound.

Farnsworth timing is about controlling the overall speed by putting pauses between the characters while training instead of slowing down the dits/dahs of the actual characters.

I don't know the science behind it, but I've spent a few hours training this way. Each set of tones that makes up a character starts to sound like its own word, or phoneme at least. It feels like it's stimulating the subconscious language bits of the brain rather than the logical/conscious ones as if you tried listening and counting the dits/dahs.