Phonetic Length

February 19, 2001
Here are some rules describing the relative lengths of vowels and consonants in different situations. These rules are described in Ladefoged (2001). All of these rules are implemented in Cynthia.


We will start with some rules describing vowel sounds.
  • Vowels are longer in open syllables than they are in syllables that are closed by a voiced consonant, which is longer than vowels in syllables that are closed by a voiceless consonant.
  • Vowels are usually longer in stressed syllables.
  • Vowels are longest in monosyllabic words, next longest in disyllabic words, and shortest in polysyllabic words.


Here are some rules about the lengths of consonants.
  • Voiceless consonants are longer than voiced connsonnats.
  • Consonants are longer when they come at the end of a word or phrase.
  • A consonant is shortened if it comes immediately before an identical consonant.
    These are called geminate consonants and only occur in English when they spread across two words as in white teeth [w ay t t iy th], or in words with two morphemes which have one of the consonants in each, such as unknown [ah n n ow n].

    Geminate consonants occur more freely in some other languages. Some examples in Italian are [n o n n ao] meaning grandfather, and [p a p p a] meaning porridge.