Complex sentence: Speakers of languages in which the same two sounds are different phonemes are attentive to the difference between them, which is an example of how different observational frames of reference leads to different patterns of attention and perception.
Split into simpler sentences: Speakers of languages in which the same two sounds are different phonemes are attentive to the difference between them. An example of how differences frame of reference of an observer leads to different patterns of attention and perception.