4.2.3 Nasalized vowels - English vowels and diphthongs are nasalized when they occur before a nasal consonant. This predictable allophonic rule of English: e.g.) bean, bone, congress [ĩ] [õ] [ã] 4.2.4 Length - Length of vowels(diphthongs) varies predictably according to the context. (a) Vowels are longer before voiced consonants than before their voiceless counterparts. Thus, the phonetic realization of the vowel /æ/ in bag [bæg] is longer than its realization in back [bæk]. (b) Vowels are longer before sonorant consonants than before obstruents. Thus the phonetic realization of the vowel /o/ in goal [gol] is longer than its realization in goad [god] (c) Vowels are longer in open syllables than in closed syllables. Thus, the phonetic realization of the vowel /e/ in bay [be] is longer than its realization in bait [bet]
Vowel Length: open syllable (knee [ni]) longer closed with sonorant consonant coda (kneel [nil]) closed with voiced obstruent coda (need [nid]) closed with voiceless consonant coda (neat [nit]) (d) Vowels are longer in stressed syllables than in unstressed syllables: e.g.) appreciate [ə.prí.ʃɪ.et] ↑ ↑ longer shorter 4.2.5 Vowels before /r/ (1) When /r/ after a vowel is the same syllable, the vowel takes on some retroflex quality, which is commonly known as “r-coloring.” e.g.) ear [ɪər], cure [kjʊər], work [wə:rk], party [pa:rti] (2) When this happens, several otherwise well-established vowel contrast of English are neutralized. Thus, the contrast between /i/ and /ɪ/ seems to disappear in words such as ear, fear, beard, pier, etc., transcribed as [ir].
(3) Neutralization of vowel quality with /r/: [ʊɚ]: tour, mature, endure, [ɛɚ]: Mary, merry, marry [ɔɚ]: pork, bore, horn, fork (4) The r-coloring is present in the following two diphthongs, resulting in triphthongs such as /eɪɚ, aɪɚ, ɔɪɚ, aʊɚ, oʊɚ/: e.g.) [aɪɚ] : fire, entire, inspire [aʊɚ] : sour, devour (5) The central vowel schwa has two r-colored manifestations: [ɚ] in unstressed syllables and [ɝ] in stressed syllables as in herder[hɝdɚ]; the r-colored vowels with the tautosyllabic /r/. cf) score, shore, organized, storm : tautosyllabic [ɔr]
4.2.6 Vowels before /l/ Postvocalic /l/ is highly velarized (dark) in American English, and this has a retracting effect on the front vowels. As a result, we have a more centralized vowel in the second words of each pair below: centralized vowel before /l/ /i/ meat - meal /ɪ/ Mick - milk /e/ pay - pale /ɛ/ bet - belt /æ/ tack - talc