Clustering of disfluencies in typical, fast and cluttered speech.

Cluttering is a fluency disorder which can be characterised by excessive disfluencies. However, the low number of studies dealing with the analysis of disfluencies in cluttering show contradictory results. The aim of this article is to analyse disfluency clusters in cluttered, fast and typical speech. Frequency of all disfluency clusters and those complex disfluencies which contain more than two constituents were analysed. The number and types of the constituents of complex disfluencies and the reason of their occurrence were analysed in detail. Results show that complex disfluencies occurred the most frequently in cluttered speech, and the least frequently in exceptionally rapid speech (ERS). Persons who clutter (PWC) had more and much longer complex disfluencies than typical speakers. Complex disfluencies which suggest difficulties in linguistic formulation occurred in cluttering significantly more times than in typical speech. The results bring us closer to understanding why there are perceptually more disfluencies in cluttered speech than in typical one. In addition, they also seem to strengthen the notion that cluttering is a language disorder.