Timing (linguistics)

In linguistics, the timing in a language comprises the rhythmic qualities of speech, in particular how syllables are distributed across time. There are two basic ways to assign time units (or beats) to words: stress timing and syllable timing.

Syllable-timed

In a syllable-timed language, every syllable is thought to take up roughly the same amount of time when pronounced, though the actual length of time of a syllable depends on situation. Spanish and French are commonly quoted as examples of syllable-timed languages. This type of rhythm was originally metaphorically referred to as 'machine-gun rhythm' because each underlying rhythmical unit is of the same duration, similar to the transient bullet noise of a machine-gun. However, since the 1950s speech scientists have tried to show the existence of equal syllable durations in the acoustic speech signal without success. More recent research claims that the duration of consonantal and vocalic intervals is responsible for syllable timed perception.

Mora-timed

Some languages, such as Japanese, are mora-timed rather than syllable-timed, but the basic concept is the same. Certain consonants in a Mora-timed language may take up the same amount of time in a rhythym as syllables, such as the Japanese syllable-final "n."

Stress-timed

In a stress-timed language, syllables may last different amounts of time, but there is a constant amount of time (on average) between two consecutive stressed syllables. English, German and Dutch are typical stress timed languages. Stress-timing is sometimes called Morse-code rhythm. When spoken faster, a stress-timed language usually shortens, obscures, or drops vowels to carry more syllables between two stresses without changing its rhythm so much.

Origin of differentiation

This difference comes from the human's two senses of rhythm. When a human hears a fast rhythm, typically faster than 330 milliseconds (ms) per beat, the series of beats is heard as one solid noise. For example, a human can imitate a machine gun sound, but hardly count its beats. Conversely, when a slow rhythm is heard, typically slower than 450 ms per beat, each beat is separately understood. The speed of a slow rhythm can be controlled beat by beat, such as hand clapping in music.

If a language has a simple syllable structure, the difference between the simplest and the most complicated syllables in the language is not wide, and it is possible to say any syllable in less than 330 ms. This includes languages that have very few consonants in each syllable. Thus we can use the fast syllable-timed rhythm. If a language has complex syllables such as ones with consonant clusters, the difference between syllables can be very wide, such as a and strengths in English. In this case, the language has slow stress-timed rhythm.

Changes in timing

These patterns can change over time or be borrowed from other languages. For example, Mexican Spanish, due to its phonetic Nahuatl substratum, shows a marked tendency towards stress timing, which makes it sound as if influenced by American English prosody. There are reports of Mexican people pronouncing "los Estados Unidos" as two "syllables", which actually means the speaker marks two beats or stress peaks (over /ta/ and /ni/), in the same way that e. g. an Argentine Spanish speaker would mark the two syllabic peaks in a word like "pompón". The pervasive vowel reduction and shortening found in English is in part a consequence of stress timing; Mexican Spanish under this influence shows signs of vowel shortening as well.

References

Kono, Morio. (1997). "Perception and Psychology of Rhythm." Accent, Intonation, Rhythm and Pause. (Japanese)

Phonetics