Chapter 4
Length of a sound
The length of a sound is the length of time during which it is held on continuously in a given word or phrase. The principal facts concerning length in English are given in the following rules:
203. Length of vowels
1. English vowels /i:/, /a:/, /?:/, /u:/, /?:/are longer than the other English vowels in similar context, i.e., when surrounded by the same sounds, and pronounced with the same degree of stress. Thus the vowels in bead /bi:d/, bard /ba:d/ board /b?:/, food /fu:d/ , bird/b?:d/ are longer than the vowels in bid /bid/, bed /bed/, lad /l?d/, rod /r?d/, bud /bΛd/, good /gud/. For this reason the vowels /i:/, /a:/, /?:/, /u:/, /?:/ are known as the long vowels, and other English vowels are known as the short vowels. The short vowels are usually half as long as the long vowels. The English diphthongs have about the same length as the ling vowels.
2. Long vowels are longer when final or followed by a voiced consonant than when followed by a voiceless consonant
In the following two pairs of sentences:
Did you see him? and What did you see?
I know him. and I don’t know.
The vowels /i:/ in the second see is longer than it is in the first one; the vowels /?u/ in the second know is longer than it is in the first one, because they are final.
Similarly the vowel /a:/ is longer in far /fa:/ or hard /ha:d/ than in heart /ha:t/ ; the vowel /ai/ is longer in lie /lai/ or lied /laid/ than in light /lait/ .
Vowels when final are even longer than when followed by a voiced consonant.
3. Long vowels and diphthongs are longer in stressed syllables than when followed by an unstressed syllable or syllables. Thus the vowel /?:/ is longer in call /k?: l/ than in calling /k?: li?/, the vowel /au/ in house /haus/ is longer than in houses /'hausiz/.
This rule is the result of a general rhythmic tendency to make stresses alternate one another in connected speech at about equal distances. Thus the /ei/ in the same thing/e? 'seim 'θi?/ is longer than that in the same sort of thing/e? 'seim s?t ?v 'θi?/. Similarly the /?:/ in I heard more /ai 'h?:d 'm?:/ is much longer than that in I heard of it in the morning/ai 'h?:d ?v it in e? 'm?:ni?/.
4. Long vowels and diphthongs are longer in stressed syllables than in unstressed syllables:
Thus the /?:/ in record /ri'k?:d/ is longer than the /?:/ in record /'r?k?:d/. Similarly the /ai/ in idle /'aidl/ is longer than the /ai/ in idea /ai'di?/.
5. Short vowels are longer before voiced consonants than before voiceless consonants. Thus the /i/ in pig /pig/ is longer than in pick /pik/.
6. Short vowels /?/, /i/ are longer and more distinct in an unstressed ending syllable than they are at the beginning of a word or in the middle of an unstressed syllable. Thus the /?/ in better /'bet?/ is longer and more distinct than it is in along /?'l??/ or in forget /f?'get/. Similarly the /i/ in happy /'h?pi/ is longer and more distinct than it is in exam /ig'z?m/ or in college /'k?li?/.
7. The short vowel /?/ is quite long when followed by voiced consonants, especially in the adjectives ending in “ad”, bad, sad, glad, etc. and in some nouns, man, bag, jam, etc. Back, that at the end of a sentence are often pronounced with long /?/.
What ‘that? When will you be back ?
204. Length of consonants: 1. Final consonants (except the plosive) are longer when preceded by a short vowel than when preceded by a long vowel or by a diphthong. Thus the /l/ in hill /hil/ is longer than that in heel /hi:l/ or that in hole /h?ul/, and the /m/ in dim /dim/ is longer than in deem /di:m/ or that in dame /deim/.
2. The sounds /m, n, ?,l/are longer when followed by voiced consonants than when followed by voiceless consonants. Thus the /n/ in bend /bend/ is longer than in bent /bent/; the /m/ in symbol /'simbl/ is longer than that in simple /'simpl/; the /l/ in cold /k?uld/ is longer than that in colt /k?ult/.