The economy of fluent speaking: Phrase-level reduction in a patient with pure apraxia of speech

Abstract

The term phrase-level reduction refers to transformations of the phonetic forms of words in connected speech. They are a characteristic property of fluent speech in normal speakers. Phrase-level reductions contribute to a reduction of articulatory-motor effort and constitute an important aspect of speech naturalness. So far, these phenomena have not been subject to clinical investigations in patients with apraxia of speech. Since apraxia of speech is considered a phonetic encoding deficit, this condition might interfere with the mechanisms involved in phrase-level reduction. In this study we investigated the types and frequencies of reduction phenomena in an individual with pure apraxia of speech and compared it with normative data from two control speakers. Analyses were based on large samples of spontaneous speech. The results are discussed against the background of theoretical accounts of phrase-level reduction.

Keywords:

• Apraxia of speech
• Phrase-level reduction
• Speech motor planning

Acknowledgements

The study was supported by a grant from the DFG-German research council (ZI 469/10-2). We would like to thank ReHa-Hilfe e.V. for their support. The study was conducted at the Neuropsychological Clinic, Clinic Bogenhausen, City-Hospital Munich and at the speech therapy department of the Neurological Clinic Bad Aibling. We are grateful to the therapists from these departments for their cooperation. We would also like to express our gratitude to all participants. Karen Croot and an anonymous reviewer are acknowledged for their thoughtful and valuable comments.

Notes

¹This patient had also participated in an earlier study (Staiger & Ziegler, 2008).

²RK produced a total of 113 complex syllables in the two speech samples. Only six of these syllables (three of them with final ‘t’-clusters) were identified as containing unmeant segment elisions. However, none of these syllables involved elisions of the final ‘t’ (e.g., ; engl. (he/she) notices). Therefore, it seems highly probable that the elisions of final ‘t’ observed in reduction syllables can virtually be ascribed to phrase-level reduction mechanisms rather than to erroneous production.