This runs in my family - women only. Grandmother, mother, myself & sister, cousin, cousin's daughter, etc. The best example I ever found to explain this was a ringing phone. At my work the phone had two ring-tones, one for internal calls and another for external calls. I couldn't tell the difference. If you played them to me one after another, then yes, I could tell they were actually different noises, but that required focus & concentration. And when the phone rang I wouldn't remember and so I just never knew if the call was coming from inside or outside the building.

I had piano lessons as a child, but for me it was all about hand-eye coordination. See those notes on the page, make these hand movements.You could have blocked my ears up with wax, and it would have made zero difference to my playing. I don't think I knew what a tune was.

My sister, much to everyone's surprise, has managed to learn basic Arabic but she was extremely motivated, and it was ten years for a basic competence. She's also a TEFL teacher, so well versed in language-learning techniques.