Predicting stuttering from phonetic complexity in German

This study investigated how phonetic complexity affects stuttering rate in German and how this changes developmentally. Phonetic difficulty was assessed using Jakielski's index [Motor Organization in the Acquisition of Consonant Clusters, Dissertation/Ph.D. Thesis, University of Texas Austin, 1998] of phonetic complexity (IPC) in which words are scored on eight different characteristics. Stuttering rate was not related to IPC score for German function words, as previously shown for Spanish and English. Significant correlations between stuttering rate and IPC score were found for content words for children over the age of six and adults. It was also found that German content words have a higher mean IPC sum compared to their English counterparts. There was a bigger difference in IPC score between fluent and stuttered words in German than in English. Factor 5 (word shape) influenced stuttering rates in both German age groups. This has also been found for Spanish but does not apply to English. Educational objectives: The reader will be able to: (1) describe a method to measure phonetic complexity and how this affects stuttering rates for words of different grammatical classes; (2) explain why this method is suitable for different languages and age groups; (3) detect which phonetic characteristics have most impact on different age groups in English and German; (4) assess possible theoretical reasons for these findings. (C) 2004 Elsevier Inc. All rights reserved.