ARTICULATION RATE
The rate (usually in syllables per second) at which the actual sounds of speech are produced by a speaker. An important distinction is made between speaking rate, based on the overall length of an utterance including pauses, and articulation rate, based on the length of the utterance with pauses deducted. When speech is perceived as ‘fast’, the impression is often mainly due to a reduction in pausing (i.e. speaking rate is significantly reduced but articulation rate is not).
Articulation rate varies between speakers and between types of speech event. It also varies within the speech of an individual. When the same speaker repeats the same phrase several times, there are small changes in the relative duration of the syllables within the phrase.
It appears that listeners are very sensitive to the articulation rate of speakers. Indeed, speed of articulation has been shown to be a factor in phoneme identification: enabling us to distinguish /ba/ from/wa/. However, because articulation rate is so variable, it is difficult to incorporate into theories of speech perception. For example, one way of dealing with the unreliability of the phoneme as a unit of perception is to suggest that listeners analyse the signal in slices of (say) a tenth of a second. But the problem then is that any given slice of connected speech will contain different amounts of phonetic information according to how fast the speaker is articulating.
Articulation rate varies from one language to another, reflecting the type of syllable structure that a given language contains. Languages also vary in how a fast speaker achieves an increase in speed of articulation. English speakers prefer to shorten unstressed syllables, to shorten vowels rather than consonants and to reorganise syllable structure by means of elision, assimilation etc.
See also: Normalisation, Pausing, Speaking rate
Further reading: Laver (1994: Chap. 17); Levelt (1989)
