I'm learning phonemes used in English. And, I came to know that there is the phenomenon called vowel reduction. Vowels get closer in the quality to schwa sound by this phenomenon.
Here is my question. I wonder if the sound qualities of different phonemes are overlapped and similar; is it hard or even impossible to identify phonemes?
In Japanese, there is no overlapped phoneme and vowel reduction, so I'm wondering why words can be identified while the timbres of phonemes can be the same with each other.