Frequency of consonant articulation errors in dysarthric speech

Area of Science:

• Speech-Language Pathology
• Neurology
• Linguistics

Background:

• Dysarthria, a motor speech disorder, frequently results from cerebral palsy (CP).
• Consonant articulation errors are a hallmark of dysarthric speech, impacting intelligibility.
• Understanding these errors is crucial for targeted speech therapy.

Purpose of the Study:

• To analyze consonant articulation errors in American-English speakers with CP-associated spastic dysarthria.
• To identify patterns in errors related to articulatory complexity, place, and manner of articulation.
• To propose a model for consonant articulation errors in this population.

Main Methods:

• Analysis of consonant phoneme transcriptions from seven native American-English speakers with CP.
• Use of diacritics to denote non-phonemic misarticulations.
• Examination of error frequencies based on target phoneme features and error-induced changes.

Main Results:

• High articulatory complexity phonemes were most frequently misarticulated, irrespective of overall speech intelligibility.
• Speakers with lower intelligibility disproportionately reduced consonant complexity.
• Errors often shifted to adjacent places of articulation, particularly in high-intelligibility speakers.
• Lower and mid-intelligibility speakers produced more manner errors than high-intelligibility speakers.

Conclusions:

• A two-part model for consonant articulation errors in spastic dysarthria is proposed.
• Articulatory complexity is a key factor in error production.
• Intelligibility level influences the nature and frequency of consonant errors in CP speech.