1. 1.2 Phonemes
Phonology is not specifically concerned with the physical properties of the speech production system.
Phoneticians are concerned with how sounds differ in the way they are pronounced while phonologists are interested in the patterning of such sounds and the rules that underlie such variations.

2. Crystal: ‘Phonological analysis relies on the principle that certain sounds cause changes in the meaning of a word or phrase, whereas other sounds do not’.
Minimal pairs test
Phonemes

6. The word ‘phoneme’ simply refers to a ‘unit of explicit sound contrast’: the existence of a minimal pair automatically grants phonemic status to the sounds responsible for the contrasts.
By selecting one type of sound instead of another we can distinguish one word from another.

7. Languages differ in the selection of contrastive sounds.
In English, the distinction between aspirated [ph] and unaspirated [p] is not phonemic.
In Chinese, however, the distinction between /p/ and /ph/ is phonemic.

8. In Chinese, the distinction between /p/ and /ph/ is phonemic, so that “宾(bīn)” and “拼(pīn)” are transcribed in IPA as /pın/ and /phın/ respectively.
The difference between the pinyin symbols b and p is not the difference of voicing but the difference of aspiration – there is no voiced /b/ in Chinese Putonghua.

9. By convention, phonemic transcriptions are placed between slant lines (/ /) while phonetic transcriptions are placed between square brackets ([ ]).
In phonetic terms, phonemic transcriptions represent the ‘broad’ transcriptions.