Coarticulation in slow speech: durational and spectral analysis.

Durational and spectral measures of anticipatory as well as perseverative coarticulation were obtained from the acoustic speech signal of German sentence utterances produced by six young female speakers at comfortable and at slowed speech rate. The test sentences comprised a systematically varied nonsense word embedded into a carrier phrase. Anticipatory and perseverative coarticulation were characterized by different patterns of durational and spectral features. Inter-speaker variability was considerable, particularly with respect to anticipatory vowel-to-vowel coarticulation. As a rule, slowing of speaking rate resulted in a decrease of perseverative coarticulation in the presence of unchanged anticipatory effects. In conclusion, these data corroborate the suggestion that different mechanisms underlie anticipatory and perseverative coarticulation.