Start here: Nabble - (teach) phonetic vs phonemic
I need help in explaining what the difference between phonemic and phonetic vowels are. Can anyone help?
In the word “bed”, three different speakers might pronounce this as [bed], [bɛd], be:d]. The vowels involved are three phonetic variants (allophones) of one phoneme /e/. These three phonetic transcriptions would all be transcribed phonemically as /bed/. By contrast [æ] is not an allophone of /e/, because /bæd/ “bad” is a different word from “bed”.