A two-case study of coarticulation in stuttered speech. An articulatory approach

This study aims to describe the coarticulatory behaviour in stuttered speech from an articulatory point of view. Its purpose is to assess the nature of transitions between a stuttered phone and preceding and subsequent phones. Two persons who stutter were recorded by means of an electromagnetic articulograph while reading a text. The vertical movements of upper and lower lips, tongue body, tongue tip and mandible were extracted. They were then analysed during a stuttering moment and linked to the acoustic type of disfluency. Our findings showed several configurations of coarticulatory behaviour in terms of supraglottic articulatory movements. While disfluencies can be the result of a disrupted coarticulatory configuration, no systematicity has been found. Moreover, all acoustic types of disfluencies are represented in several coarticulatory configurations. Therefore, a stuttering-like disfluency is not always due to a coarticulatory disturbance, since correct coarticulatory patterns can be observed both between the disfluent sound and its previous and subsequent sounds. Furthermore, they suggest that the acoustic classification of disfluencies does not seem important for the coarticulatory behaviour.