B07 Sound patterns in Human Language: syllables

We have made passing reference to syllables at several points in this course. We noted that we could usually spot syllables in a waveform like that below (butterfly, flutter by) by looking at the rise and fall of signal energy. Each syllable seems to rise to a maximum and fall off again. But things are not quite that simple. Even here, you can see that the syllables // and // each have two peaks. That is, the energy falls off a little in the middle as the diphthong changes from // to //. So signal intensity alone is not a reliable guide to identifying syllables.

How many syllables do these words have?

You will probably have no difficulty with the first row. Some of the others can be pronounced in various ways, e.g. /../ which is 3 syllables with a syllabic //, or as /./, which is 2 syllables only. With others, such as hour or fire, there may be no good answer to the question of how many syllables there are. So although syllabification is easy most of the time, it sometimes just isn't clear.

Sometimes it is also difficult to say just where one syllable ends and the next begins. Ladefoged gives happy as an example. Is this /./ or /./? The /p/ is said to be ambisyllabic, as it might reasonably be considered to belong to either syllable.

One attempt to formalize the notion of relative intensity is the concept of sonority. Sonority can be defined with reference to the acoustic signal, in which case it refers to the relative intensity of a sound compared with other sounds spoken in as similar a manner as possible. Sonority can also be defined with reference to the relative openness of the vocal tract-the more open it is, the more sonorous the sound. Either way, we get a relative ordering which is roughly:

There are further fine differences within each category, e.g. low vowels are more sonorous than high vowels.

Syllables can now be described as having a sonority profile. For most syllables, the most sonorous sound is in the middle, and is called the syllable nucleus, while the sounds on either end of the nucleus are less sonorous. In words in which there are clear peaks of sonority, e.g. condensation or absolutely we tend to have an easy time dividing the word into syllables, and we would all agree on the number of syllables in each. For a word like seal, however, the sonority profile is less clear, as the final /l/ might constitute a separate sonority peak for some speakers but not for others.

The idea of a sonority profile for each syllable runs into problems with words like spanks where the /sp/ and /ks/ sequences each place a sound of low sonority (/p/ or /k/) closer to the syllable nucleus than their respective /s/ sounds. Some languages, notably Polish, abound in such violations of the principle we suggested above. Investigation of syllable structure is an area of considerable interest to researchers at the moment.

Syllable structure

We will return to syllables in the latter part of this course.