Different dialects of a language may use different phonemes for the same word.
The end result was the perception of a third, different phoneme.
This is often for historical reasons (these Polish letters originally stood for different phonemes, which merged later).
Furthermore, speakers of languages are attentive to sounds, particularly if the same two sounds come from different phonemes.
Every vowel occurred in long and short versions which were different phonemes in the first syllable.
Finally, it is difficult for children to hear and produce all of the different phonemes of a given language.
A further distinction between the different phonemes are found in the context of d-effect (for which, see the d-effect section).
In some languages, like Albanian, those two sounds are different phonemes.
The macron has no unique value, and is simply used to distinguish between two different phonemes.
This suggests that they may belong to different phonemes, and that is indeed a common analysis.