coarticulation (n.)

An ARTICULATION which involves in a simultaneous or over lapping way more than one point in the VOCAL TRACT, as in the co-ordinate STOPS  often heard in West African languages. In anticipatory coarticulation, an articulator not involved in a particular sound begins to move in the direction of an articulation needed for a later sound in the UTTERANCE (its TARGET). An example is the sh- of shoe, which is normally pronounced with lip-ROUNDING, anticipating the influence of the following [u:]. In perseverative or perseveratory coarticulation, a sound retains a characteristic deriving from an earlier articulation, as when the [n] in seen is articulated slightly further forward than the [n] in soon. Alternative terms include right-to-left (for anticipatory) and left-to-right (for perseverative) coarticulation.