I'm not buying that explanation. Hearing, just like seeing, is something that you need to practice. If it's the first time you're hearing a specific sound then you might not notice the intricate details in it. If you stick around those sounds for long enough then you'll hear the details as well.
When I was younger I knew a girl whose voice I did not understand when I first met her. It took me some time before I was able to understand what she was saying, because I hadn't heard a voice like that before. Based on that event, I think that the reason people can't hear the specific details of pronunciation is because they're not used to it, but they can learn with more experience.
Agreed. Create audio samples of all relevant phonemes and listen to them 10x per day for a week or two. That should be enough to discriminate them -- or I'll eat my hat.
'Course it would then take further training to be actually able to speak them.
When I was younger I knew a girl whose voice I did not understand when I first met her. It took me some time before I was able to understand what she was saying, because I hadn't heard a voice like that before. Based on that event, I think that the reason people can't hear the specific details of pronunciation is because they're not used to it, but they can learn with more experience.